vb.net recording variation of change in listview

I am looking for assistance with code the displays the change in value of a column in a list view

example this column changes every 3 seconds.  It clears the listview and writes the new values
so the column values would need to be store before clearing the some comparing of stored value to new value

let say these are the start values
column 0    Column 1
1                   0
2                   0
4                   0
2                   0
3                   0
5                   0

after 3 second

column 0              Column 1
1 goes to 4           3
2 goes to 3           1
4 goes to 1           -3
2 goes to 5           3
3 goes to 1           -2
5 goes to 4           -1

the code i am working with is

#Region "RunnerPoolDristrabution"
    Private poollist As New ArrayList
    Public Sub RunnerDistrabution()
        Dim i As Decimal = 0
        Dim ipool As Decimal = 0
        Dim q As Decimal = 0
        Dim count As Integer = 0



        For Each item As ListViewItem In ListView7.Items

            i = (winpool - ipool) / CDec(item.SubItems(1).Text)
            item.SubItems(8).Text = (i + (0.2 * i)).ToString("N2")
            If poollist(count).ToString <> item.SubItems(8).Text Then
                poollist.    ((i + (0.2 * i)).ToString("N2"))
            End If
            ipool = ipool + i
            count += 1
        Next
        For Each item As ListViewItem In ListView7.Items
            q = CDec(item.SubItems(8).Text)
            item.SubItems(9).Text = (i + (0.2 * i) - CDec(q)).ToString("N2")
        Next


    End Sub

#End Region