diff --git a/src/DataFrame-Tests/DataSeriesTest.class.st b/src/DataFrame-Tests/DataSeriesTest.class.st
index 9847c149..08eea389 100644
--- a/src/DataFrame-Tests/DataSeriesTest.class.st
+++ b/src/DataFrame-Tests/DataSeriesTest.class.st
@@ -1058,6 +1058,32 @@ DataSeriesTest >> testCopyChangeDoesNotAffectOriginal [
 	self assert: original equals: expectedOriginalAfterChange
 ]
 
+{ #category : #'tests - statistics' }
+DataSeriesTest >> testCountNils [
+
+	| seriesWithNils |
+	keyArray := #( a b c d e f g h i j k ).
+
+	seriesWithNils := DataSeries
+		                  withKeys: keyArray
+		                  values: #( 3 7 6 20 nil 9 nil 10 15 13 nil )
+		                  name: 'ExampleSeries'.
+	self assert: seriesWithNils countNils equals: 3
+]
+
+{ #category : #'tests - statistics' }
+DataSeriesTest >> testCountNonNils [
+
+	| seriesWithNils |
+	keyArray := #( a b c d e f g h i j k ).
+
+	seriesWithNils := DataSeries
+		                  withKeys: keyArray
+		                  values: #( 3 7 6 20 nil 9 nil 10 15 13 nil )
+		                  name: 'ExampleSeries'.
+	self assert: seriesWithNils countNonNils equals: 8
+]
+
 { #category : #'tests - creation' }
 DataSeriesTest >> testCreateDataSeriesAsDataSeries [
 
diff --git a/src/DataFrame/DataSeries.class.st b/src/DataFrame/DataSeries.class.st
index 877c255a..3d03c778 100644
--- a/src/DataFrame/DataSeries.class.st
+++ b/src/DataFrame/DataSeries.class.st
@@ -236,6 +236,20 @@ DataSeries >> correlationWith: otherSeries using: aCorrelationCoefficient [
 	^ aCorrelationCoefficient between: self and: otherSeries
 ]
 
+{ #category : #statistics }
+DataSeries >> countNils [
+	"Returns the number of nil values in the data series"
+
+	^ self count: [ :each | each isNil ]
+]
+
+{ #category : #statistics }
+DataSeries >> countNonNils [
+	"Returns the number of non-nil values in the data series"
+
+	^ self count: [ :each | each isNotNil ]
+]
+
 { #category : #statistics }
 DataSeries >> crossTabulateWith: aSeries [
 	"A DataFrame is returned which is useful in quantitatively analyzing the relationship of values in one data series with the values in another data series"