Return array of ListViewItem to Sub

Question

I want to make a chart with several series on it. Every series belongs to a particular person.

First I read out the number of different persons in my table in Access:

connection.Open()
    command.CommandText = "SELECT kontoverlauf_kunden_id FROM kontoverlauf GROUP BY kontoverlauf_kunden_id"

    Dim kunden_id_array As New ArrayList()

    reader = command.ExecuteReader()

    Do While reader.Read()
        kunden_id_array.Add(reader("kontoverlauf_kunden_id").ToString())
    Loop
    reader.Close()
    connection.Close()

Now I have the different persons (the ID of them). Second I add the series i need to the chart:

For counter As Integer = 0 To kunden_id_array.Count - 1
        chartKontoverlauf.Series.Add(New Series("Konto [" & kunden_id_array.Item(counter) & "]"))
        chartKontoverlauf.Series(counter).ChartType = SeriesChartType.Line
        chartKontoverlauf.Series(counter).Color = Color.Red
        chartKontoverlauf.Series(counter).BorderWidth = 3
Next

Now I just need to fill in the points I need, but that's kinda tricky. I've made a function that will call every time and it reads out the values (money and time) for the particular person. Here's the function first:

Function DatenAuslesen(ByVal kunden_id As Integer) As ListViewItem
Dim lstViewItem As New ListViewItem
Try
    connection.Open()
    command.CommandText = "SELECT * FROM kontoverlauf WHERE kontoverlauf_kunden_id = " & kunden_id
    reader = command.ExecuteReader()

    Do While reader.Read()
        lstViewItem.SubItems.Add(reader("kontoverlauf_wert").ToString())
        lstViewItem.SubItems.Add(reader("kontoverlauf_datum").ToString())
    Loop
    reader.Close()
    connection.Close()
Catch ex As Exception
    MsgBox(ex.Message)
End Try
connection.Close()
Return lstViewItem
End Function

To add the points now, I wrote this little thing:

For counter As Integer = 0 To kunden_id_array.Count - 1
        For counter_2 As Integer = 0 To DatenAuslesen(kunden_id_array.Item(counter)).ListView.Items.Count - 1
            chartKontoverlauf.Series(counter).Points.AddXY(DatenAuslesen(kunden_id_array.Item(counter)).ListView.Items(counter_2).SubItems(0).Text, DatenAuslesen(kunden_id_array.Item(counter)).ListView.Items(counter_2).SubItems(1).Text)
        Next
    Next

The problem with the thing is that it just gives me one of the values I need back, and not all. I can't access alle values properly. I'm still not sure if it's even the best variable to do this. I would need an array of ListViewItems to add all of them but I didn't found how to do this.

Maybe anyone has an idea? Thank you!