diff --git a/core/include/Data/ArrayData.h b/core/include/Data/ArrayData.h
index ab14657..16f54fe 100644
--- a/core/include/Data/ArrayData.h
+++ b/core/include/Data/ArrayData.h
@@ -94,7 +94,6 @@ public:
     }
 
     int distance(const ArrayDataIteratorValue::Impl &other) const override try {
-        /// @todo ALX : validate
         const auto &otherImpl = dynamic_cast<const IteratorValue &>(other);
         return std::distance(otherImpl.m_It, m_It) / m_NbComponents;
     }
diff --git a/core/include/Data/DataSeries.h b/core/include/Data/DataSeries.h
index dff18f8..e7d74c9 100644
--- a/core/include/Data/DataSeries.h
+++ b/core/include/Data/DataSeries.h
@@ -146,7 +146,7 @@ public:
     /// @sa IDataSeries::valuesUnit()
     Unit valuesUnit() const override { return m_ValuesUnit; }
 
-    int nbPoints() const override { return m_XAxisData->totalSize() + m_ValuesData->totalSize(); }
+    int nbPoints() const override { return m_ValuesData->totalSize(); }
 
     void clear()
     {
diff --git a/core/include/Data/IDataSeries.h b/core/include/Data/IDataSeries.h
index 19778fb..44ed1dd 100644
--- a/core/include/Data/IDataSeries.h
+++ b/core/include/Data/IDataSeries.h
@@ -4,6 +4,7 @@
 #include <Common/MetaTypes.h>
 #include <Data/DataSeriesIterator.h>
 #include <Data/SqpRange.h>
+#include <Data/Unit.h>
 
 #include <memory>
 
@@ -12,22 +13,6 @@
 template <int Dim>
 class ArrayData;
 
-struct Unit {
-    explicit Unit(const QString &name = {}, bool timeUnit = false)
-            : m_Name{name}, m_TimeUnit{timeUnit}
-    {
-    }
-
-    inline bool operator==(const Unit &other) const
-    {
-        return std::tie(m_Name, m_TimeUnit) == std::tie(other.m_Name, other.m_TimeUnit);
-    }
-    inline bool operator!=(const Unit &other) const { return !(*this == other); }
-
-    QString m_Name;  ///< Unit name
-    bool m_TimeUnit; ///< The unit is a unit of time (UTC)
-};
-
 /**
  * @brief The IDataSeries aims to declare a data series.
  *
diff --git a/core/include/Data/Unit.h b/core/include/Data/Unit.h
new file mode 100644
index 0000000..24cdc47
--- /dev/null
+++ b/core/include/Data/Unit.h
@@ -0,0 +1,23 @@
+#ifndef SCIQLOP_UNIT_H
+#define SCIQLOP_UNIT_H
+
+#include <QString>
+#include <tuple>
+
+struct Unit {
+    explicit Unit(const QString &name = {}, bool timeUnit = false)
+            : m_Name{name}, m_TimeUnit{timeUnit}
+    {
+    }
+
+    inline bool operator==(const Unit &other) const
+    {
+        return std::tie(m_Name, m_TimeUnit) == std::tie(other.m_Name, other.m_TimeUnit);
+    }
+    inline bool operator!=(const Unit &other) const { return !(*this == other); }
+
+    QString m_Name;  ///< Unit name
+    bool m_TimeUnit; ///< The unit is a unit of time (UTC)
+};
+
+#endif // SCIQLOP_UNIT_H
diff --git a/core/tests/Variable/TestVariable.cpp b/core/tests/Variable/TestVariable.cpp
index e3389e8..a8fca16 100644
--- a/core/tests/Variable/TestVariable.cpp
+++ b/core/tests/Variable/TestVariable.cpp
@@ -296,21 +296,21 @@ void TestVariable::testNbPoints_data()
     // ////////// //
     NbPointsOperations operations{};
 
-    // Sets cache range (expected nb points = series xAxis data + series values data)
+    // Sets cache range (expected nb points = values data)
     auto cacheRange = SqpRange{date(2017, 1, 1, 12, 0, 0), date(2017, 1, 1, 12, 0, 9)};
-    operations.push_back({cacheRange, dataSeries(cacheRange), 20});
+    operations.push_back({cacheRange, dataSeries(cacheRange), 10});
 
     // Doubles cache but don't add data series (expected nb points don't change)
     cacheRange = SqpRange{date(2017, 1, 1, 12, 0, 0), date(2017, 1, 1, 12, 0, 19)};
-    operations.push_back({cacheRange, dataSeries(INVALID_RANGE), 20});
+    operations.push_back({cacheRange, dataSeries(INVALID_RANGE), 10});
 
     // Doubles cache and data series (expected nb points change)
     cacheRange = SqpRange{date(2017, 1, 1, 12, 0, 0), date(2017, 1, 1, 12, 0, 19)};
-    operations.push_back({cacheRange, dataSeries(cacheRange), 40});
+    operations.push_back({cacheRange, dataSeries(cacheRange), 20});
 
     // Decreases cache (expected nb points decreases as the series is purged)
     cacheRange = SqpRange{date(2017, 1, 1, 12, 0, 5), date(2017, 1, 1, 12, 0, 9)};
-    operations.push_back({cacheRange, dataSeries(INVALID_RANGE), 10});
+    operations.push_back({cacheRange, dataSeries(INVALID_RANGE), 5});
 
     QTest::newRow("nbPoints1") << operations;
 }