Private Sub Kategoriehäufigkeit()
        Dim dt1 As New DataTable("Kategoriehäufigkeit")
        dt1.Columns.Add("Kategorie", GetType(String))
        dt1.Columns.Add("Anzahl", GetType(Integer))
        dt1.Columns.Add("Gesamtbetrag", GetType(Double))
 
        For Each d1 In From d As DataRow In ArchivDB.Kontodetails.AsEnumerable( _
          ) Group d By _
          Kategorie = d.Field(Of String)("Kategorie") Into g = Group _
          Select Kategorie, g.Count
            Dim dr1 As DataRow = dt1.NewRow
            dr1("Kategorie") = d1.Kategorie
            dr1("Anzahl") = d1.Count
            dr1("Gesamtbetrag") = ??
            dt1.Rows.Add(dr1)
        Next
 
        DataGridView1.DataSource = dt1
        With ChartKategorie
            .Series.Clear()
            .Series.Add("default")
            .Series("default").ChartType = _
              DataVisualization.Charting.SeriesChartType.Pie
            .DataSource = dt1
            .Series("default").XValueMember = "Kategorie"
            .Series("default").YValueMembers = "Anzahl"
        End With
    End Sub