I’m trying to sum the values of column11, grouping by the value of column14.
The table is like this:

My code looks like this, the result its close but the numbers are not right yet:
Edit*

    Dim chartValues = New Dictionary(Of String, Integer)()

    For Each row In DataGridView1.Rows.OfType(Of DataGridViewRow)
        Dim column14Value = row.Cells().Item("Column14").Value.ToString()
        Dim column11Value = row.Cells().Item("Column11").Value

        If (chartValues.ContainsKey(column14Value)) Then
            chartValues(column14Value) = chartValues(column14Value) + column11Value
        Else
            chartValues.Add(column14Value, column11Value)
        End If
    Next
    For Each chartValue In chartValues
            Chart1.Series(0).Points.AddXY(chartValue.Key, chartValue.Value)
            Chart1.ChartAreas(0).AxisX.Interval = 1
    Next

The result that I want is this:

Any help is really appreciated. Thanks!