diff --git a/ApplicationLibCode/Application/Tools/RiaStatisticsTools.cpp b/ApplicationLibCode/Application/Tools/RiaStatisticsTools.cpp
index 09e568ce92..5605065f65 100644
--- a/ApplicationLibCode/Application/Tools/RiaStatisticsTools.cpp
+++ b/ApplicationLibCode/Application/Tools/RiaStatisticsTools.cpp
@@ -20,39 +20,8 @@
 
 #include "RiaStatisticsTools.h"
 
-#include "RifEclipseSummaryAddress.h"
 #include "RigStatisticsMath.h"
 
-#include "cafAssert.h"
-
-#include <QString>
-
-//--------------------------------------------------------------------------------------------------
-///
-//--------------------------------------------------------------------------------------------------
-const QString RiaStatisticsTools::replacePercentileByPValueText( const QString& percentile )
-{
-    QString result = percentile;
-
-    if ( result == ENSEMBLE_STAT_P10_QUANTITY_NAME )
-    {
-        result = ENSEMBLE_STAT_P90_QUANTITY_NAME;
-    }
-    else if ( result == ENSEMBLE_STAT_P90_QUANTITY_NAME )
-    {
-        result = ENSEMBLE_STAT_P10_QUANTITY_NAME;
-    }
-    else if ( percentile.contains( QString( "%1:" ).arg( ENSEMBLE_STAT_P10_QUANTITY_NAME ) ) )
-    {
-        result.replace( ENSEMBLE_STAT_P10_QUANTITY_NAME, ENSEMBLE_STAT_P90_QUANTITY_NAME );
-    }
-    else if ( percentile.contains( QString( "%1:" ).arg( ENSEMBLE_STAT_P90_QUANTITY_NAME ) ) )
-    {
-        result.replace( ENSEMBLE_STAT_P90_QUANTITY_NAME, ENSEMBLE_STAT_P10_QUANTITY_NAME );
-    }
-    return result;
-}
-
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
diff --git a/ApplicationLibCode/Application/Tools/RiaStatisticsTools.h b/ApplicationLibCode/Application/Tools/RiaStatisticsTools.h
index 58b3315e65..94ab689e04 100644
--- a/ApplicationLibCode/Application/Tools/RiaStatisticsTools.h
+++ b/ApplicationLibCode/Application/Tools/RiaStatisticsTools.h
@@ -24,8 +24,6 @@
 #include <numeric>
 #include <vector>
 
-class QString;
-
 //==================================================================================================
 //
 //
@@ -34,8 +32,6 @@ class QString;
 class RiaStatisticsTools
 {
 public:
-    static const QString replacePercentileByPValueText( const QString& percentile );
-
     template <class NumberType>
     static bool isInvalidNumber( NumberType value )
     {
diff --git a/ApplicationLibCode/FileInterface/RifReaderEnsembleStatisticsRft.cpp b/ApplicationLibCode/FileInterface/RifReaderEnsembleStatisticsRft.cpp
index dcbca7f567..b47c0ef84d 100644
--- a/ApplicationLibCode/FileInterface/RifReaderEnsembleStatisticsRft.cpp
+++ b/ApplicationLibCode/FileInterface/RifReaderEnsembleStatisticsRft.cpp
@@ -240,7 +240,12 @@ void RifReaderEnsembleStatisticsRft::calculateStatistics( const RifEclipseRftAdd
                 pressuresAtDepth.push_back( curvePressures[depthIdx] );
             }
             double p10, p50, p90, mean;
-            RigStatisticsMath::calculateStatisticsCurves( pressuresAtDepth, &p10, &p50, &p90, &mean );
+            RigStatisticsMath::calculateStatisticsCurves( pressuresAtDepth,
+                                                          &p10,
+                                                          &p50,
+                                                          &p90,
+                                                          &mean,
+                                                          RigStatisticsMath::PercentileStyle::SWITCHED );
 
             m_cachedValues[depthAddress].push_back( allDepths[depthIdx] );
 
diff --git a/ApplicationLibCode/ProjectDataModel/Completions/RimEnsembleFractureStatistics.cpp b/ApplicationLibCode/ProjectDataModel/Completions/RimEnsembleFractureStatistics.cpp
index cf3a001a89..6ca364472f 100644
--- a/ApplicationLibCode/ProjectDataModel/Completions/RimEnsembleFractureStatistics.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Completions/RimEnsembleFractureStatistics.cpp
@@ -1131,7 +1131,12 @@ void RimEnsembleFractureStatistics::generateStatisticsGrids(
                 double p50;
                 double p90;
                 double mean;
-                RigStatisticsMath::calculateStatisticsCurves( samples[idx], &p10, &p50, &p90, &mean );
+                RigStatisticsMath::calculateStatisticsCurves( samples[idx],
+                                                              &p10,
+                                                              &p50,
+                                                              &p90,
+                                                              &mean,
+                                                              RigStatisticsMath::PercentileStyle::SWITCHED );
 
                 if ( calculateP10 )
                     setValueNoInf( statisticsGrids[RimEnsembleFractureStatistics::StatisticsType::P10], x, y, p10 );
diff --git a/ApplicationLibCode/ProjectDataModel/CorrelationPlots/RimCorrelationPlot.cpp b/ApplicationLibCode/ProjectDataModel/CorrelationPlots/RimCorrelationPlot.cpp
index bc7ab92030..00cb8e2063 100644
--- a/ApplicationLibCode/ProjectDataModel/CorrelationPlots/RimCorrelationPlot.cpp
+++ b/ApplicationLibCode/ProjectDataModel/CorrelationPlots/RimCorrelationPlot.cpp
@@ -20,7 +20,6 @@
 
 #include "RiaPreferences.h"
 #include "RiaQDateTimeTools.h"
-#include "RiaStatisticsTools.h"
 #include "RiuGroupedBarChartBuilder.h"
 #include "RiuPlotMainWindowTools.h"
 #include "RiuQwtPlotWidget.h"
diff --git a/ApplicationLibCode/ProjectDataModel/CorrelationPlots/RimParameterResultCrossPlot.cpp b/ApplicationLibCode/ProjectDataModel/CorrelationPlots/RimParameterResultCrossPlot.cpp
index f557be7172..84d8dd3ef3 100644
--- a/ApplicationLibCode/ProjectDataModel/CorrelationPlots/RimParameterResultCrossPlot.cpp
+++ b/ApplicationLibCode/ProjectDataModel/CorrelationPlots/RimParameterResultCrossPlot.cpp
@@ -21,7 +21,6 @@
 #include "RiaColorTables.h"
 #include "RiaPreferences.h"
 #include "RiaQDateTimeTools.h"
-#include "RiaStatisticsTools.h"
 #include "RiaTextStringTools.h"
 
 #include "RifSummaryReaderInterface.h"
diff --git a/ApplicationLibCode/ProjectDataModel/Flow/RimWellRftPlot.cpp b/ApplicationLibCode/ProjectDataModel/Flow/RimWellRftPlot.cpp
index fac4a21bff..d5fc47f905 100644
--- a/ApplicationLibCode/ProjectDataModel/Flow/RimWellRftPlot.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Flow/RimWellRftPlot.cpp
@@ -22,7 +22,6 @@
 #include "RiaColorTools.h"
 #include "RiaDateStringParser.h"
 #include "RiaSimWellBranchTools.h"
-#include "RiaStatisticsTools.h"
 
 #include "RifReaderEclipseRft.h"
 
@@ -582,7 +581,6 @@ void RimWellRftPlot::updateCurvesInPlot( const std::set<RiaRftPltCurveDefinition
                     QString uiText =
                         caf::AppEnum<RifEclipseRftAddress::RftWellLogChannelType>::uiText( rftAddress.wellLogChannel() );
                     QString label = uiText.replace( ": Pressure", "" );
-                    label         = RiaStatisticsTools::replacePercentileByPValueText( label );
                     curve->setSymbolLabel( label );
                     curve->setLineThickness( 3 );
                 }
diff --git a/ApplicationLibCode/ProjectDataModel/Rim3dOverlayInfoConfig.cpp b/ApplicationLibCode/ProjectDataModel/Rim3dOverlayInfoConfig.cpp
index a9caf7b119..3033f04ca2 100644
--- a/ApplicationLibCode/ProjectDataModel/Rim3dOverlayInfoConfig.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Rim3dOverlayInfoConfig.cpp
@@ -481,9 +481,9 @@ QString Rim3dOverlayInfoConfig::resultInfoText( const RigHistogramData& histData
                              "<tr> <td>%1</td>  <td> %2</td> <td>  %3</td> <td> %4</td> <td> %5</td> <td> %6</td> </tr>"
                              "</table>" )
                         .arg( histData.min )
-                        .arg( histData.p10 )
-                        .arg( histData.mean )
                         .arg( histData.p90 )
+                        .arg( histData.mean )
+                        .arg( histData.p10 )
                         .arg( histData.max )
                         .arg( histData.sum );
             }
@@ -652,9 +652,9 @@ QString Rim3dOverlayInfoConfig::resultInfoText( const RigHistogramData& histData
                             "<tr> <td>%1</td>  <td> %2</td> <td> %3</td>  <td> %4</td> <td> %5</td> <td> %6</td> </tr>"
                             "</table>" )
                             .arg( histData.min )
-                            .arg( histData.p10 )
-                            .arg( histData.mean )
                             .arg( histData.p90 )
+                            .arg( histData.mean )
+                            .arg( histData.p10 )
                             .arg( histData.max )
                             .arg( histData.sum );
                 }
@@ -863,7 +863,7 @@ void Rim3dOverlayInfoConfig::updateEclipse3DInfo( RimEclipseView* eclipseView )
         {
             eclipseView->viewer()->showHistogram( true );
             eclipseView->viewer()->setHistogram( histData.min, histData.max, histData.histogram );
-            eclipseView->viewer()->setHistogramPercentiles( histData.p10, histData.p90, histData.mean );
+            eclipseView->viewer()->setHistogramPercentiles( histData.p90, histData.p10, histData.mean );
         }
     }
 }
@@ -912,7 +912,7 @@ void Rim3dOverlayInfoConfig::updateGeoMech3DInfo( RimGeoMechView* geoMechView )
         {
             geoMechView->viewer()->showHistogram( true );
             geoMechView->viewer()->setHistogram( histData.min, histData.max, histData.histogram );
-            geoMechView->viewer()->setHistogramPercentiles( histData.p10, histData.p90, histData.mean );
+            geoMechView->viewer()->setHistogramPercentiles( histData.p90, histData.p10, histData.mean );
         }
     }
 }
diff --git a/ApplicationLibCode/ProjectDataModel/RimEclipseStatisticsCaseEvaluator.cpp b/ApplicationLibCode/ProjectDataModel/RimEclipseStatisticsCaseEvaluator.cpp
index 6a3422e517..624c1a3472 100644
--- a/ApplicationLibCode/ProjectDataModel/RimEclipseStatisticsCaseEvaluator.cpp
+++ b/ApplicationLibCode/ProjectDataModel/RimEclipseStatisticsCaseEvaluator.cpp
@@ -97,10 +97,7 @@ QString createResultNameRange( const QString& resultName )
 }
 QString createResultNamePVal( const QString& resultName, double pValPos )
 {
-    // Invert the number for display text
-    double valueForDisplay = 100.0 - pValPos;
-
-    return resultName + "_P" + QString::number( valueForDisplay );
+    return resultName + "_P" + QString::number( pValPos );
 }
 
 //--------------------------------------------------------------------------------------------------
@@ -296,7 +293,9 @@ void RimEclipseStatisticsCaseEvaluator::evaluateForResults( const QList<ResSpec>
                                     pValPoss.push_back( m_statisticsConfig.m_pMidPos );
                                     pValPoss.push_back( m_statisticsConfig.m_pMaxPos );
                                     std::vector<double> pVals =
-                                        RigStatisticsMath::calculateNearestRankPercentiles( values, pValPoss );
+                                        RigStatisticsMath::calculateNearestRankPercentiles( values,
+                                                                                            pValPoss,
+                                                                                            RigStatisticsMath::PercentileStyle::SWITCHED );
                                     statParams[PMIN] = pVals[0];
                                     statParams[PMID] = pVals[1];
                                     statParams[PMAX] = pVals[2];
@@ -306,9 +305,15 @@ void RimEclipseStatisticsCaseEvaluator::evaluateForResults( const QList<ResSpec>
                                     std::vector<size_t>    histogram;
                                     RigHistogramCalculator histCalc( statParams[MIN], statParams[MAX], 100, &histogram );
                                     histCalc.addData( values );
-                                    statParams[PMIN] = histCalc.calculatePercentil( m_statisticsConfig.m_pMinPos / 100.0 );
-                                    statParams[PMID] = histCalc.calculatePercentil( m_statisticsConfig.m_pMidPos / 100.0 );
-                                    statParams[PMAX] = histCalc.calculatePercentil( m_statisticsConfig.m_pMaxPos / 100.0 );
+                                    statParams[PMIN] =
+                                        histCalc.calculatePercentil( m_statisticsConfig.m_pMinPos / 100.0,
+                                                                     RigStatisticsMath::PercentileStyle::SWITCHED );
+                                    statParams[PMID] =
+                                        histCalc.calculatePercentil( m_statisticsConfig.m_pMidPos / 100.0,
+                                                                     RigStatisticsMath::PercentileStyle::SWITCHED );
+                                    statParams[PMAX] =
+                                        histCalc.calculatePercentil( m_statisticsConfig.m_pMaxPos / 100.0,
+                                                                     RigStatisticsMath::PercentileStyle::SWITCHED );
                                 }
                                 else if ( m_statisticsConfig.m_pValMethod ==
                                           RimEclipseStatisticsCase::INTERPOLATED_OBSERVATION )
@@ -318,7 +323,9 @@ void RimEclipseStatisticsCaseEvaluator::evaluateForResults( const QList<ResSpec>
                                     pValPoss.push_back( m_statisticsConfig.m_pMidPos );
                                     pValPoss.push_back( m_statisticsConfig.m_pMaxPos );
                                     std::vector<double> pVals =
-                                        RigStatisticsMath::calculateInterpolatedPercentiles( values, pValPoss );
+                                        RigStatisticsMath::calculateInterpolatedPercentiles( values,
+                                                                                             pValPoss,
+                                                                                             RigStatisticsMath::PercentileStyle::SWITCHED );
                                     statParams[PMIN] = pVals[0];
                                     statParams[PMID] = pVals[1];
                                     statParams[PMAX] = pVals[2];
diff --git a/ApplicationLibCode/ProjectDataModel/RimStatisticsPlot.cpp b/ApplicationLibCode/ProjectDataModel/RimStatisticsPlot.cpp
index b12d7d6715..2092f656dd 100644
--- a/ApplicationLibCode/ProjectDataModel/RimStatisticsPlot.cpp
+++ b/ApplicationLibCode/ProjectDataModel/RimStatisticsPlot.cpp
@@ -365,7 +365,7 @@ void RimStatisticsPlot::updatePlots()
         p10series->attachAxis( axisY );
     }
 
-    if ( !std::isinf( histogramData.p10 ) )
+    if ( !std::isinf( histogramData.p90 ) )
     {
         QLineSeries* p90series = new QLineSeries();
         chart->addSeries( p90series );
diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleCurveSet.cpp b/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleCurveSet.cpp
index e2f3b82908..1e8d90f375 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleCurveSet.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleCurveSet.cpp
@@ -22,7 +22,6 @@
 #include "RiaGuiApplication.h"
 #include "RiaPreferences.h"
 #include "RiaResultNames.h"
-#include "RiaStatisticsTools.h"
 #include "RiaSummaryCurveAnalyzer.h"
 #include "RiaSummaryCurveDefinition.h"
 #include "RiaTimeTTools.h"
@@ -31,8 +30,6 @@
 
 #include "RifEnsembleStatisticsReader.h"
 
-#include "RigStatisticsMath.h"
-
 #include "RimCustomObjectiveFunction.h"
 #include "RimCustomObjectiveFunctionCollection.h"
 #include "RimDerivedEnsembleCaseCollection.h"
@@ -1804,8 +1801,7 @@ void RimEnsembleCurveSet::updateStatisticsCurves( const std::vector<RimSummaryCa
         curve->setSymbolSkipDistance( 150 );
         if ( m_statistics->showCurveLabels() )
         {
-            curve->setSymbolLabel( RiaStatisticsTools::replacePercentileByPValueText(
-                QString::fromStdString( address.ensembleStatisticsQuantityName() ) ) );
+            curve->setSymbolLabel( QString::fromStdString( address.ensembleStatisticsQuantityName() ) );
         }
         curve->setLineStyle( RiuQwtPlotCurveDefines::LineStyleEnum::STYLE_SOLID );
         curve->setSummaryCaseY( m_ensembleStatCase.get() );
diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleStatistics.cpp b/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleStatistics.cpp
index 906c9130f7..76b04bc47b 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleStatistics.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleStatistics.cpp
@@ -37,9 +37,9 @@ RimEnsembleStatistics::RimEnsembleStatistics( RimEnsembleCurveSetInterface* pare
     CAF_PDM_InitField( &m_active, "Active", true, "Show Statistics Curves", "", "", "" );
     CAF_PDM_InitField( &m_hideEnsembleCurves, "HideEnsembleCurves", false, "Hide Ensemble Curves", "", "", "" );
     CAF_PDM_InitField( &m_basedOnFilteredCases, "BasedOnFilteredCases", false, "Based on Filtered Cases", "", "", "" );
-    CAF_PDM_InitField( &m_showP10Curve, "ShowP10Curve", true, "P90", "", "", "" ); // Yes, P90
+    CAF_PDM_InitField( &m_showP10Curve, "ShowP10Curve", true, "P10", "", "", "" );
     CAF_PDM_InitField( &m_showP50Curve, "ShowP50Curve", false, "P50", "", "", "" );
-    CAF_PDM_InitField( &m_showP90Curve, "ShowP90Curve", true, "P10", "", "", "" ); // Yes, P10
+    CAF_PDM_InitField( &m_showP90Curve, "ShowP90Curve", true, "P90", "", "", "" );
     CAF_PDM_InitField( &m_showMeanCurve, "ShowMeanCurve", true, "Mean", "", "", "" );
     CAF_PDM_InitField( &m_showCurveLabels, "ShowCurveLabels", true, "Show Curve Labels", "", "", "" );
     CAF_PDM_InitField( &m_includeIncompleteCurves, "IncludeIncompleteCurves", false, "Include Incomplete Curves", "", "", "" );
@@ -149,8 +149,8 @@ void RimEnsembleStatistics::defineUiOrdering( QString uiConfigName, caf::PdmUiOr
     m_showCurveLabels.uiCapability()->setUiReadOnly( !m_active );
     m_color.uiCapability()->setUiReadOnly( !m_active );
 
-    m_showP10Curve.uiCapability()->setUiName( curveSet->hasP10Data() ? "P90" : "P90 (Needs > 8 curves)" );
-    m_showP90Curve.uiCapability()->setUiName( curveSet->hasP90Data() ? "P10" : "P10 (Needs > 8 curves)" );
+    m_showP10Curve.uiCapability()->setUiName( curveSet->hasP10Data() ? "P10" : "P10 (Needs > 8 curves)" );
+    m_showP90Curve.uiCapability()->setUiName( curveSet->hasP90Data() ? "P90" : "P90 (Needs > 8 curves)" );
 
     uiOrdering.skipRemainingFields( true );
 }
diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleStatisticsCase.cpp b/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleStatisticsCase.cpp
index 44abd72023..30113951f4 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleStatisticsCase.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimEnsembleStatisticsCase.cpp
@@ -188,8 +188,12 @@ void RimEnsembleStatisticsCase::calculate( const std::vector<RimSummaryCase*> su
         }
 
         double p10, p50, p90, mean;
-        RigStatisticsMath::calculateStatisticsCurves( valuesAtTimeStep, &p10, &p50, &p90, &mean );
-
+        RigStatisticsMath::calculateStatisticsCurves( valuesAtTimeStep,
+                                                      &p10,
+                                                      &p50,
+                                                      &p90,
+                                                      &mean,
+                                                      RigStatisticsMath::PercentileStyle::SWITCHED );
         m_p10Data.push_back( p10 );
         m_p50Data.push_back( p50 );
         m_p90Data.push_back( p90 );
diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.cpp b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.cpp
index 1ae4e4b872..58f53ea7f3 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.cpp
@@ -24,7 +24,6 @@
 #include "RiaLogging.h"
 #include "RiaPreferencesSummary.h"
 #include "RiaResultNames.h"
-#include "RiaStatisticsTools.h"
 #include "RiaSummaryCurveDefinition.h"
 #include "RiaSummaryTools.h"
 
@@ -941,11 +940,6 @@ QString RimSummaryCurve::curveExportDescription( const RifEclipseSummaryAddress&
     auto group    = curveSet ? curveSet->summaryCaseCollection() : nullptr;
 
     auto addressUiText = addr.uiText();
-    if ( addr.category() == RifEclipseSummaryAddress::SUMMARY_ENSEMBLE_STATISTICS )
-    {
-        addressUiText =
-            RiaStatisticsTools::replacePercentileByPValueText( QString::fromStdString( addressUiText ) ).toStdString();
-    }
 
     if ( group && group->isEnsemble() )
     {
diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurveAutoName.cpp b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurveAutoName.cpp
index dac2d8d849..ac6459e6df 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurveAutoName.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurveAutoName.cpp
@@ -18,8 +18,6 @@
 
 #include "RimSummaryCurveAutoName.h"
 
-#include "RiaStatisticsTools.h"
-
 #include "RifEclipseSummaryAddress.h"
 
 #include "RimEnsembleCurveSet.h"
@@ -196,9 +194,7 @@ QString RimSummaryCurveAutoName::buildCurveName( const RifEclipseSummaryAddress&
 
         if ( summaryAddress.category() == RifEclipseSummaryAddress::SUMMARY_ENSEMBLE_STATISTICS )
         {
-            text = RiaStatisticsTools::replacePercentileByPValueText(
-                       QString::fromStdString( summaryAddress.quantityName() ) )
-                       .toStdString();
+            text = summaryAddress.quantityName();
         }
         else if ( summaryAddress.category() == RifEclipseSummaryAddress::SUMMARY_CALCULATED )
         {
diff --git a/ApplicationLibCode/ProjectDataModel/WellLog/RimEnsembleWellLogStatistics.cpp b/ApplicationLibCode/ProjectDataModel/WellLog/RimEnsembleWellLogStatistics.cpp
index 5256547e88..932ccd9ad8 100644
--- a/ApplicationLibCode/ProjectDataModel/WellLog/RimEnsembleWellLogStatistics.cpp
+++ b/ApplicationLibCode/ProjectDataModel/WellLog/RimEnsembleWellLogStatistics.cpp
@@ -145,7 +145,12 @@ void RimEnsembleWellLogStatistics::calculate( const std::vector<RimWellLogFile*>
                 valuesAtDepth.push_back( curveValues[depthIdx] );
             }
             double p10, p50, p90, mean;
-            RigStatisticsMath::calculateStatisticsCurves( valuesAtDepth, &p10, &p50, &p90, &mean );
+            RigStatisticsMath::calculateStatisticsCurves( valuesAtDepth,
+                                                          &p10,
+                                                          &p50,
+                                                          &p90,
+                                                          &mean,
+                                                          RigStatisticsMath::PercentileStyle::SWITCHED );
 
             m_measuredDepths.push_back( allDepths[depthIdx] );
             m_p10Data.push_back( p10 );
@@ -216,7 +221,12 @@ void RimEnsembleWellLogStatistics::calculateByKLayer( const std::vector<RimWellL
         {
             std::vector<double> valuesAtDepth = topValues[kIndex];
             double              p10, p50, p90, mean;
-            RigStatisticsMath::calculateStatisticsCurves( valuesAtDepth, &p10, &p50, &p90, &mean );
+            RigStatisticsMath::calculateStatisticsCurves( valuesAtDepth,
+                                                          &p10,
+                                                          &p50,
+                                                          &p90,
+                                                          &mean,
+                                                          RigStatisticsMath::PercentileStyle::SWITCHED );
             m_measuredDepths.push_back( offsets->getTopDepth( kIndex ) );
             m_p10Data.push_back( p10 );
             m_p50Data.push_back( p50 );
@@ -230,7 +240,12 @@ void RimEnsembleWellLogStatistics::calculateByKLayer( const std::vector<RimWellL
         {
             std::vector<double> valuesAtDepth = bottomValues[kIndex];
             double              p10, p50, p90, mean;
-            RigStatisticsMath::calculateStatisticsCurves( valuesAtDepth, &p10, &p50, &p90, &mean );
+            RigStatisticsMath::calculateStatisticsCurves( valuesAtDepth,
+                                                          &p10,
+                                                          &p50,
+                                                          &p90,
+                                                          &mean,
+                                                          RigStatisticsMath::PercentileStyle::SWITCHED );
             m_measuredDepths.push_back( offsets->getBottomDepth( kIndex ) );
             m_p10Data.push_back( p10 );
             m_p50Data.push_back( p50 );
diff --git a/ApplicationLibCode/ProjectDataModel/WellLog/RimWellLogRftCurve.cpp b/ApplicationLibCode/ProjectDataModel/WellLog/RimWellLogRftCurve.cpp
index 008f8ff534..491e77398b 100644
--- a/ApplicationLibCode/ProjectDataModel/WellLog/RimWellLogRftCurve.cpp
+++ b/ApplicationLibCode/ProjectDataModel/WellLog/RimWellLogRftCurve.cpp
@@ -22,7 +22,6 @@
 #include "RiaEclipseUnitTools.h"
 #include "RiaQDateTimeTools.h"
 #include "RiaSimWellBranchTools.h"
-#include "RiaStatisticsTools.h"
 
 #include "RifEclipseRftAddress.h"
 #include "RifReaderEclipseRft.h"
@@ -359,7 +358,6 @@ QString RimWellLogRftCurve::createCurveAutoName()
         RifEclipseRftAddress::RftWellLogChannelType channelNameEnum =
             caf::AppEnum<RifEclipseRftAddress::RftWellLogChannelType>::fromText( wellLogChannelUiName() );
         QString channelName = caf::AppEnum<RifEclipseRftAddress::RftWellLogChannelType>::uiText( channelNameEnum );
-        channelName         = RiaStatisticsTools::replacePercentileByPValueText( channelName );
         name.push_back( channelName );
     }
     if ( !m_timeStep().isNull() )
diff --git a/ApplicationLibCode/ReservoirDataModel/RigEnsembleFractureStatisticsCalculator.cpp b/ApplicationLibCode/ReservoirDataModel/RigEnsembleFractureStatisticsCalculator.cpp
index a575ba36ee..e3065fbcb8 100644
--- a/ApplicationLibCode/ReservoirDataModel/RigEnsembleFractureStatisticsCalculator.cpp
+++ b/ApplicationLibCode/ReservoirDataModel/RigEnsembleFractureStatisticsCalculator.cpp
@@ -127,7 +127,12 @@ RigHistogramData RigEnsembleFractureStatisticsCalculator::createStatisticsData(
 
     double p50;
     double mean;
-    RigStatisticsMath::calculateStatisticsCurves( samples, &histogramData.p10, &p50, &histogramData.p90, &mean );
+    RigStatisticsMath::calculateStatisticsCurves( samples,
+                                                  &histogramData.p10,
+                                                  &p50,
+                                                  &histogramData.p90,
+                                                  &mean,
+                                                  RigStatisticsMath::PercentileStyle::SWITCHED );
 
     std::vector<size_t>    histogram;
     RigHistogramCalculator histogramCalculator( histogramData.min, histogramData.max, numBins, &histogram );
diff --git a/ApplicationLibCode/ReservoirDataModel/RigSurfaceStatisticsCalculator.cpp b/ApplicationLibCode/ReservoirDataModel/RigSurfaceStatisticsCalculator.cpp
index 479086b0c7..e7c74823c9 100644
--- a/ApplicationLibCode/ReservoirDataModel/RigSurfaceStatisticsCalculator.cpp
+++ b/ApplicationLibCode/ReservoirDataModel/RigSurfaceStatisticsCalculator.cpp
@@ -82,7 +82,12 @@ cvf::ref<RigSurface> RigSurfaceStatisticsCalculator::computeStatistics( const st
         double p10;
         double p50;
         double p90;
-        RigStatisticsMath::calculateStatisticsCurves( samples, &p10, &p50, &p90, &mean );
+        RigStatisticsMath::calculateStatisticsCurves( samples,
+                                                      &p10,
+                                                      &p50,
+                                                      &p90,
+                                                      &mean,
+                                                      RigStatisticsMath::PercentileStyle::SWITCHED );
 
         // TODO: improve handling of these cases
         auto makeValid = []( double val ) {
diff --git a/ApplicationLibCode/ResultStatisticsCache/RigStatisticsDataCache.cpp b/ApplicationLibCode/ResultStatisticsCache/RigStatisticsDataCache.cpp
index 87c44a4c0a..72e37c971b 100644
--- a/ApplicationLibCode/ResultStatisticsCache/RigStatisticsDataCache.cpp
+++ b/ApplicationLibCode/ResultStatisticsCache/RigStatisticsDataCache.cpp
@@ -343,8 +343,8 @@ void RigStatisticsDataCache::computeHistogramStatisticsIfNeeded()
 
         m_statisticsCalculator->addDataToHistogramCalculator( histCalc );
 
-        m_statsAllTimesteps.m_p10 = histCalc.calculatePercentil( 0.1 );
-        m_statsAllTimesteps.m_p90 = histCalc.calculatePercentil( 0.9 );
+        m_statsAllTimesteps.m_p10 = histCalc.calculatePercentil( 0.1, RigStatisticsMath::PercentileStyle::SWITCHED );
+        m_statsAllTimesteps.m_p90 = histCalc.calculatePercentil( 0.9, RigStatisticsMath::PercentileStyle::SWITCHED );
     }
 }
 
@@ -364,8 +364,8 @@ void RigStatisticsDataCache::computeHistogramStatisticsIfNeeded( size_t timeStep
 
         m_statisticsCalculator->addDataToHistogramCalculator( timeStepIndex, histCalc );
 
-        m_statsPrTs[timeStepIndex].m_p10 = histCalc.calculatePercentil( 0.1 );
-        m_statsPrTs[timeStepIndex].m_p90 = histCalc.calculatePercentil( 0.9 );
+        m_statsPrTs[timeStepIndex].m_p10 = histCalc.calculatePercentil( 0.1, RigStatisticsMath::PercentileStyle::SWITCHED );
+        m_statsPrTs[timeStepIndex].m_p90 = histCalc.calculatePercentil( 0.9, RigStatisticsMath::PercentileStyle::SWITCHED );
     }
 }
 
diff --git a/ApplicationLibCode/ResultStatisticsCache/RigStatisticsMath.cpp b/ApplicationLibCode/ResultStatisticsCache/RigStatisticsMath.cpp
index 88154b68f8..0ae38b380b 100644
--- a/ApplicationLibCode/ResultStatisticsCache/RigStatisticsMath.cpp
+++ b/ApplicationLibCode/ResultStatisticsCache/RigStatisticsMath.cpp
@@ -91,7 +91,8 @@ void RigStatisticsMath::calculateStatisticsCurves( const std::vector<double>& va
                                                    double*                    p10,
                                                    double*                    p50,
                                                    double*                    p90,
-                                                   double*                    mean )
+                                                   double*                    mean,
+                                                   PercentileStyle            percentileStyle )
 {
     CVF_ASSERT( p10 && p50 && p90 && mean );
 
@@ -145,9 +146,20 @@ void RigStatisticsMath::calculateStatisticsCurves( const std::vector<double>& va
         }
     }
 
-    *p10  = pValues[P10];
-    *p50  = pValues[P50];
-    *p90  = pValues[P90];
+    *p50 = pValues[P50];
+
+    if ( percentileStyle == PercentileStyle::REGULAR )
+    {
+        *p10 = pValues[P10];
+        *p90 = pValues[P90];
+    }
+    else
+    {
+        CVF_ASSERT( percentileStyle == PercentileStyle::SWITCHED );
+        *p10 = pValues[P90];
+        *p90 = pValues[P10];
+    }
+
     *mean = valueSum / valueCount;
 }
 
@@ -158,7 +170,8 @@ void RigStatisticsMath::calculateStatisticsCurves( const std::vector<double>& va
 //--------------------------------------------------------------------------------------------------
 
 std::vector<double> RigStatisticsMath::calculateNearestRankPercentiles( const std::vector<double>& inputValues,
-                                                                        const std::vector<double>& pValPositions )
+                                                                        const std::vector<double>& pValPositions,
+                                                                        RigStatisticsMath::PercentileStyle percentileStyle )
 {
     std::vector<double> sortedValues;
     sortedValues.reserve( inputValues.size() );
@@ -180,7 +193,10 @@ std::vector<double> RigStatisticsMath::calculateNearestRankPercentiles( const st
         {
             double pVal = HUGE_VAL;
 
-            size_t pValIndex = static_cast<size_t>( sortedValues.size() * cvf::Math::abs( pValPositions[i] ) / 100 );
+            double pValPosition = cvf::Math::abs( pValPositions[i] ) / 100;
+            if ( percentileStyle == RigStatisticsMath::PercentileStyle::SWITCHED ) pValPosition = 1.0 - pValPosition;
+
+            size_t pValIndex = static_cast<size_t>( sortedValues.size() * pValPosition );
 
             if ( pValIndex >= sortedValues.size() ) pValIndex = sortedValues.size() - 1;
 
@@ -198,7 +214,8 @@ std::vector<double> RigStatisticsMath::calculateNearestRankPercentiles( const st
 /// the inputValues does not contain any valid values
 //--------------------------------------------------------------------------------------------------
 std::vector<double> RigStatisticsMath::calculateInterpolatedPercentiles( const std::vector<double>& inputValues,
-                                                                         const std::vector<double>& pValPositions )
+                                                                         const std::vector<double>& pValPositions,
+                                                                         RigStatisticsMath::PercentileStyle percentileStyle )
 {
     std::vector<double> sortedValues;
     sortedValues.reserve( inputValues.size() );
@@ -220,7 +237,10 @@ std::vector<double> RigStatisticsMath::calculateInterpolatedPercentiles( const s
         {
             double pVal = HUGE_VAL;
 
-            double doubleIndex = ( sortedValues.size() - 1 ) * cvf::Math::abs( pValPositions[i] ) / 100.0;
+            double pValPosition = cvf::Math::abs( pValPositions[i] ) / 100.0;
+            if ( percentileStyle == RigStatisticsMath::PercentileStyle::SWITCHED ) pValPosition = 1.0 - pValPosition;
+
+            double doubleIndex = ( sortedValues.size() - 1 ) * pValPosition;
 
             size_t lowerValueIndex = static_cast<size_t>( floor( doubleIndex ) );
             size_t upperValueIndex = lowerValueIndex + 1;
@@ -315,12 +335,16 @@ void RigHistogramCalculator::addData( const std::vector<float>& data )
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
-double RigHistogramCalculator::calculatePercentil( double pVal )
+double RigHistogramCalculator::calculatePercentil( double pVal, RigStatisticsMath::PercentileStyle percentileStyle )
 {
     assert( m_histogram );
     assert( m_histogram->size() );
     auto pValClamped = cvf::Math::clamp( pVal, 0.0, 1.0 );
     assert( 0.0 <= pValClamped && pValClamped <= 1.0 );
+    if ( percentileStyle == RigStatisticsMath::PercentileStyle::SWITCHED )
+    {
+        pValClamped = 1.0 - pValClamped;
+    }
 
     double pValObservationCount = pValClamped * m_observationCount;
     if ( pValObservationCount == 0.0 ) return m_min;
diff --git a/ApplicationLibCode/ResultStatisticsCache/RigStatisticsMath.h b/ApplicationLibCode/ResultStatisticsCache/RigStatisticsMath.h
index 8d4992b0c6..b1209edb07 100644
--- a/ApplicationLibCode/ResultStatisticsCache/RigStatisticsMath.h
+++ b/ApplicationLibCode/ResultStatisticsCache/RigStatisticsMath.h
@@ -27,6 +27,12 @@
 class RigStatisticsMath
 {
 public:
+    enum class PercentileStyle
+    {
+        REGULAR,
+        SWITCHED
+    };
+
     static void calculateBasicStatistics( const std::vector<double>& values,
                                           double*                    min,
                                           double*                    max,
@@ -34,13 +40,21 @@ public:
                                           double*                    range,
                                           double*                    mean,
                                           double*                    dev );
-    static void
-        calculateStatisticsCurves( const std::vector<double>& values, double* p10, double* p50, double* p90, double* mean );
+
+    static void calculateStatisticsCurves( const std::vector<double>& values,
+                                           double*                    p10,
+                                           double*                    p50,
+                                           double*                    p90,
+                                           double*                    mean,
+                                           PercentileStyle            percentileStyle );
 
     static std::vector<double> calculateNearestRankPercentiles( const std::vector<double>& inputValues,
-                                                                const std::vector<double>& pValPositions );
+                                                                const std::vector<double>& pValPositions,
+                                                                PercentileStyle            percentileStyle );
+
     static std::vector<double> calculateInterpolatedPercentiles( const std::vector<double>& inputValues,
-                                                                 const std::vector<double>& pValPositions );
+                                                                 const std::vector<double>& pValPositions,
+                                                                 PercentileStyle            percentileStyle );
 };
 
 //==================================================================================================
@@ -61,7 +75,7 @@ public:
     /// the percentile is the domain value at which pVal of the observations are below it.
     /// Will only consider observed values between min and max, as all other values are discarded from the histogram
 
-    double calculatePercentil( double pVal );
+    double calculatePercentil( double pVal, RigStatisticsMath::PercentileStyle percentileStyle );
 
 private:
     size_t               m_maxIndex;
diff --git a/ApplicationLibCode/UnitTests/RigStatisticsMath-Test.cpp b/ApplicationLibCode/UnitTests/RigStatisticsMath-Test.cpp
index 899777b474..17e42e4c6a 100644
--- a/ApplicationLibCode/UnitTests/RigStatisticsMath-Test.cpp
+++ b/ApplicationLibCode/UnitTests/RigStatisticsMath-Test.cpp
@@ -86,7 +86,8 @@ TEST( RigStatisticsMath, RankPercentiles )
     pValPos.push_back( 40 );
     pValPos.push_back( 50 );
     pValPos.push_back( 90 );
-    std::vector<double> pVals = RigStatisticsMath::calculateNearestRankPercentiles( values, pValPos );
+    std::vector<double> pVals =
+        RigStatisticsMath::calculateNearestRankPercentiles( values, pValPos, RigStatisticsMath::PercentileStyle::REGULAR );
 
     EXPECT_DOUBLE_EQ( -76092.8157632591000, pVals[0] );
     EXPECT_DOUBLE_EQ( 2788.2723335651900, pVals[1] );
@@ -126,9 +127,9 @@ TEST( RigStatisticsMath, HistogramPercentiles )
     histCalc.addData( values );
 
     double p10, p50, p90;
-    p10 = histCalc.calculatePercentil( 0.1 );
-    p50 = histCalc.calculatePercentil( 0.5 );
-    p90 = histCalc.calculatePercentil( 0.9 );
+    p10 = histCalc.calculatePercentil( 0.1, RigStatisticsMath::PercentileStyle::REGULAR );
+    p50 = histCalc.calculatePercentil( 0.5, RigStatisticsMath::PercentileStyle::REGULAR );
+    p90 = histCalc.calculatePercentil( 0.9, RigStatisticsMath::PercentileStyle::REGULAR );
 
     EXPECT_DOUBLE_EQ( -76273.240559989776, p10 );
     EXPECT_DOUBLE_EQ( 5312.1312871307755, p50 );
@@ -164,10 +165,11 @@ TEST( RigStatisticsMath, InterpolatedPercentiles )
     pValPos.push_back( 40 );
     pValPos.push_back( 50 );
     pValPos.push_back( 90 );
-    std::vector<double> pVals = RigStatisticsMath::calculateInterpolatedPercentiles( values, pValPos );
+    std::vector<double> pVals =
+        RigStatisticsMath::calculateInterpolatedPercentiles( values, pValPos, RigStatisticsMath::PercentileStyle::REGULAR );
 
     EXPECT_DOUBLE_EQ( -72278.340409937548, pVals[0] );
-    EXPECT_DOUBLE_EQ( -2265.6006907818719, pVals[1] );
+    EXPECT_DOUBLE_EQ( -2265.6006907818496, pVals[1] );
     EXPECT_DOUBLE_EQ( 6391.9799990972897, pVals[2] );
     EXPECT_DOUBLE_EQ( 93073.49128098879, pVals[3] );
 }
@@ -226,6 +228,8 @@ TEST( RigStatisticsMath, Accumulators )
 //--------------------------------------------------------------------------------------------------
 TEST( RigStatisticsMath, calculateStatisticsCurves )
 {
+    RigStatisticsMath::PercentileStyle percentileStyle = RigStatisticsMath::PercentileStyle::REGULAR;
+
     {
         std::vector<double> values;
 
@@ -234,7 +238,7 @@ TEST( RigStatisticsMath, calculateStatisticsCurves )
         double p50  = HUGE_VAL;
         double p90  = HUGE_VAL;
 
-        RigStatisticsMath::calculateStatisticsCurves( values, &p10, &p50, &p90, &mean );
+        RigStatisticsMath::calculateStatisticsCurves( values, &p10, &p50, &p90, &mean, percentileStyle );
         EXPECT_TRUE( std::isinf( p10 ) );
         EXPECT_TRUE( std::isinf( p50 ) );
         EXPECT_TRUE( std::isinf( p90 ) );
@@ -254,7 +258,7 @@ TEST( RigStatisticsMath, calculateStatisticsCurves )
         double p90  = HUGE_VAL;
 
         // If we have few samples, P10 and P90 cannot be computed
-        RigStatisticsMath::calculateStatisticsCurves( values, &p10, &p50, &p90, &mean );
+        RigStatisticsMath::calculateStatisticsCurves( values, &p10, &p50, &p90, &mean, percentileStyle );
         EXPECT_TRUE( std::isinf( p10 ) );
         EXPECT_TRUE( std::isinf( p90 ) );
         EXPECT_DOUBLE_EQ( 1.0, p50 );
@@ -269,7 +273,7 @@ TEST( RigStatisticsMath, calculateStatisticsCurves )
         double p50  = HUGE_VAL;
         double p90  = HUGE_VAL;
 
-        RigStatisticsMath::calculateStatisticsCurves( values, &p10, &p50, &p90, &mean );
+        RigStatisticsMath::calculateStatisticsCurves( values, &p10, &p50, &p90, &mean, percentileStyle );
         EXPECT_DOUBLE_EQ( 1.0, p10 );
         EXPECT_DOUBLE_EQ( 1.0, p50 );
         EXPECT_FALSE( std::isinf( p90 ) );
@@ -284,7 +288,7 @@ TEST( RigStatisticsMath, calculateStatisticsCurves )
         double p50  = HUGE_VAL;
         double p90  = HUGE_VAL;
 
-        RigStatisticsMath::calculateStatisticsCurves( values, &p10, &p50, &p90, &mean );
+        RigStatisticsMath::calculateStatisticsCurves( values, &p10, &p50, &p90, &mean, percentileStyle );
         EXPECT_DOUBLE_EQ( 1.0, p10 );
         EXPECT_DOUBLE_EQ( 1.0, p50 );
         EXPECT_DOUBLE_EQ( 1.0, p90 );
diff --git a/ApplicationLibCode/UnitTests/RigSurfaceStatisticsCalculator-Test.cpp b/ApplicationLibCode/UnitTests/RigSurfaceStatisticsCalculator-Test.cpp
index 1e9aa1d1e7..5a68147422 100644
--- a/ApplicationLibCode/UnitTests/RigSurfaceStatisticsCalculator-Test.cpp
+++ b/ApplicationLibCode/UnitTests/RigSurfaceStatisticsCalculator-Test.cpp
@@ -74,8 +74,8 @@ TEST( RigSurfaceStatisticsTests, computeStatistics )
         ASSERT_EQ( 49.5, meanValues[i] );
         ASSERT_EQ( 0, minValues[i] );
         ASSERT_EQ( 99, maxValues[i] );
-        ASSERT_NEAR( 9.1, p10Values[i], 0.0001 );
+        ASSERT_NEAR( 9.1, p90Values[i], 0.0001 );
         ASSERT_NEAR( 49.5, p50Values[i], 0.0001 );
-        ASSERT_NEAR( 89.9, p90Values[i], 0.0001 );
+        ASSERT_NEAR( 89.9, p10Values[i], 0.0001 );
     }
 }