Show countdown while generating page

Dim PreviousPageTitle As String = Page.Title
Dim TotalIterations As Integer = 1000
Dim StartTime As DateTime = Now
    For CurrentInteration As Integer = 0 To TotalIterations
        If CurrentInteration > 0 Then
            Dim RemainingIterations As Integer = TotalIterations - CurrentInteration
            Dim RemainingProgressPercent As Single = 1 - CurrentInteration / TotalIterations
            Dim TimePassed As TimeSpan = Now - StartTime
            Dim TimeToEnd As New TimeSpan(TotalIterations * TimePassed.Ticks / CurrentInteration)
            Dim TimeRemaining As TimeSpan = TimeToEnd - TimePassed
            Threading.Thread.Sleep(18)
            Response.Flush()
            Response.Write(String.Format("<script>document.title = '{0} {1} {2}'</script>", RemainingIterations, TimeRemaining.ToString("m':'ss"), RemainingProgressPercent.ToString("p1")))
        End If
    Next CurrentInteration
Page.Title = PreviousPageTitle
Response.Write("<script>document.title = '" & PreviousPageTitle & "'</script>")