Private Sub Verbrauch_berechnen()
 Dim kwhverbraucht As Double
 
        For Zeile As Integer = 0 To DGVStrom.Rows.Count - 1
            If DGVStrom.CurrentCell.RowIndex = 0 Then
                DGVStrom.Rows(Zeile).Cells(5).Value = "erste Ablesung"
            Else
                DGVStrom.Rows(Zeile).Cells(4).Value ??????
            End If
        Next Zeile
End Sub