With dt.Columns
      .Add("ID", GetType(Integer))
      .Add("Störung Zeit", GetType(Date))
      .Add("Störung Ort", GetType(String))
      .Add("Störung Dauer", GetType(Integer))
      .Add("Störung Art", GetType(Integer))
      .Add("Maschine ID", GetType(Integer))
 End With

 Private Function GetFreq1(ByVal week As Integer, _
        year As Integer, masch As Integer) As DataTable
 
     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)("Störung Zeit"), _
             Globalization.CalendarWeekRule.FirstDay, DayOfWeek.Monday)
           Where year = row.Field(Of Date)("Störung Zeit").Year _
             AndAlso wk = week _
             AndAlso row.Field(Of Integer)("Maschine ID") = masch
           Group By art = row.Field(Of Integer)("Störung Art") Into Count()
 
     Dim df As New DataTable
     df.Columns.Add("Störung Art") : df.Columns.Add("Count")
 
     For Each el In q
        df.Rows.Add(el.art, el.Count)
     Next el
 
     Return df
End Function