Private Sub Button1_Click_1(sender As Object, e As EventArgs) Handles _
  Button1.Click
        GetFreq1(3, 2017, 2)
    End Sub
    Private Function GetFreq1(ByVal week As Integer, _
      year As Integer, masch As Integer) As DataTable
        Dim dt As DataTable = TPMDB.Stoerungen
        Dim cal As Globalization.Calendar = _
           Globalization.CultureInfo.CurrentCulture.Calendar
 
        Dim q = From row As DataRow In dt
              Let wk As Integer = _
                cal.GetWeekOfYear(row.Field(Of Date)("Eintrag"), _
                Globalization.CalendarWeekRule.FirstDay, DayOfWeek.Monday)
              Where year = row.Field(Of Date)("Eintrag").Year _
                AndAlso wk = week _
                AndAlso row.Field(Of Integer)("MaschinenID") = masch
              Group By art = row.Field(Of String)("ArtderStörung") Into Count()
 
        Dim df As New DataTable
        df.Columns.Add("ArtderStörung") : df.Columns.Add("Count")
 
        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"
 
        DataGridView1.DataSource = bs
 
 
        Return df
    End Function