主题：请教一个“率”应如何算出

Dim dt As DataTable = DataTables("表A")
Dim tss As List(Of String) = dt.GetUniqueValues("[用户名称] Is Not NULL","用户名称")
For Each ts As String In tss
    Dim drs As List(Of DataRow) = dt.Select("[用户名称] = '" & ts & "'", "投诉时间")
    For i As integer = 1 To drs.Count - 1
        Dim t As TimeSpan = drs(i)("投诉时间") - drs(i-1)("投诉时间")
        drs(i)("第十列") = t.Days
    Next
Next

For Each dr As DataRow In dt.DataRows
    Dim Count As Integer = dt.Compute("Count(用户名称)","[用户名称] = '" & dr("用户名称") & "'")
    Dim Count1 As Integer = dt.Compute("Count(第十列)","[用户名称] = '" & dr("用户名称") & "' And [第十列] = 0")
    If dr.IsNull("投诉时间") = false Then
        dr("重复投诉率") = Count1 / Count * 100
    End If
Next