Dim q = From row As DataRow In dt
            Let wk As Integer =
                cal.GetWeekOfYear(row.Field(Of Date)("Eintrag"),
                Globalization.CalendarWeekRule.FirstFourDayWeek,
                DayOfWeek.Monday)
            Let Minuten = row.Field(Of Integer)("Stoerdauer")
            Let Instandhaltung = row.Field(Of String)("Eintrag-Instandhaltung")
            Where year = row.Field(Of Date)("Eintrag").Year _
                 AndAlso wk = week _
                 AndAlso row.Field(Of Integer)("MaschID") = masch _
                 AndAlso row.Field(Of String)("Eintrag-Instandhaltung") <> Text
            Group By art = Instandhaltung Into Sum(Minuten), Count