Fastest way to find and count same items VB6

For zz1 = 0 To List1.ListCount - 1
  DoEvents
gg = ""
gg = List1.List(zz1)
    For zz2 = zz1 To List1.ListCount - 1
        If gg = List1.List(zz2) And gg <> "" Then
            countit = countit + 1
            List1.List(zz2) = ""
        End If
    Next zz2
        If countit <> 0 Then
            List2.AddItem gg & "," & countit
            countit = 0
        End If
Next zz1