Option Explicit
'
Private Sub Worksheet_Change(ByVal Target As Range)
Dim Graph As Chart, Spl() As String, PlgDat As Range, PlgVal As Range, L As Long
Set Graph = Me.ChartObjects("Graphique 1").Chart
Spl = Split(Graph.SeriesCollection(1).Formula, ",")
Set PlgDat = Range(Spl(1))
Set PlgVal = Range(Spl(2))
L = PlgDat.Rows.Count
Application.EnableEvents = False
If CVDate(PlgDat.Rows(L).Value) < Date Then
With Range(PlgDat, PlgVal).Rows(L): .Copy: .Insert xlShiftDown: End With
L = L + 1: PlgDat.Rows(L).Value = Date
End If
PlgVal.Rows(L).Value = Me.[MaSomme].Value
Application.EnableEvents = True
End Sub