Private Sub Monatsliste()
        Dim lst_Monate As New List(Of String) From {"", "Januar", "Februar", _
          "März", "April", "Mai", "Juni", "Juli", "August", "September", _
          "Oktober", "November", "Dezember"}
        cbx_Monat.Items.AddRange(lst_Monate.ToArray)
        cbx_Monat.SelectedIndex = 0
        lst_Monate.Clear()
    End Sub

 Dim dt As DataTable = ABLAGEPUAM.Vorgang
        Dim cal As Globalization.Calendar = _
          Globalization.CultureInfo.CurrentCulture.Calendar
 
        Dim q = From row As DataRow In dt
              Let mn As Integer = row.Field(Of Date)("angelegtam").Month
              Where year = row.Field(Of Date)("angelegtam").Year _
               AndAlso mn = Month(row.Field(Of Date)("angelegtam")) _
              Group By art = row.Field(Of String)("Ablagename") Into Count()
 
        Dim df As New DataTable
        df.Columns.Add("Ablagename") : df.Columns.Add("Count", GetType( _
          Integer)) : df.Columns.Add("Cum", GetType(Double)) _
                                        : df.Columns.Add("CumPerc", GetType( _
                                        Double))
 
        For Each el In q
            df.Rows.Add(el.art, el.Count)
        Next el
 
        Dim bs As New BindingSource With {.DataSource = df}
        bs.Sort = "Count DESC"
 
        Dim sm As Integer = 0
        For i As Integer = 0 To bs.Count - 1
            Dim row As DataRow = DirectCast(bs(i), DataRowView).Row
            'Häufigkeiten kumulieren
            sm += CInt(row("Count"))
            row("cum") = sm
        Next i
 
        'Kumulierte Werte in Prozentanteile umrechnen
        For i As Integer = 0 To bs.Count - 1
            Dim row As DataRow = DirectCast(bs(i), DataRowView).Row
            row("CumPerc") = Math.Round(CInt(row("Cum")) / sm * 100, 2)
        Next i
 
        'Daten in der DGV anzeigen
        DGV1.DataSource = bs