VB.NET Velocità di download espressa in KB - DownloadFileAsync

[aizenn]

Salve, vorrei visualizzare in una label la velocità di download espressa in kb, io per scaricare un file uso questo codice:

Public WithEvents TCP As New System.Net.WebClient

Public Mem1 As String, Mem2 As String

  Private Sub PrgChngd(ByVal sender As Object, ByVal e As System.Net.DownloadProgressChangedEventArgs) Handles TCP.DownloadProgressChanged        ProgressBar1.Value = e.ProgressPercentage
        If e.TotalBytesToReceive > 1073741824 Then
            Mem1 = Math.Round((((e.TotalBytesToReceive / 1024) / 1024) / 1024), 2) & " GB"
        Else
            Mem1 = Math.Round((((e.TotalBytesToReceive / 1024) / 1024)), 2) & " MB"
        End If
        Label3.Text = Mem1


        If e.BytesReceived > 1073741824 Then
            Mem2 = Math.Round((((e.BytesReceived / 1024) / 1024) / 1024), 2) & " GB"
        Else
            Mem2 = Math.Round((((e.BytesReceived / 1024) / 1024)), 2) & " MB"
        End If
        Label4.Text = Mem2
        Label5.Text = e.ProgressPercentage & "%"
    End Sub


    Private Sub PrgComplete(ByVal sender As Object, ByVal e As System.ComponentModel.AsyncCompletedEventArgs) Handles TCP.DownloadFileCompleted
        If e.Cancelled = True Then
            MessageBox.Show("Errore! Il download non è stato completato!", "Errore!", MessageBoxButtons.OK, MessageBoxIcon.Error)
        Else
            MessageBox.Show("Il Download è stato completato con successo!", "Download Completo", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End If


        Button1.Text = "Scarica"
    End Sub

    Public Sub Download()
        If Button1.Text = "Scarica" Then
            On Error GoTo Err
            SaveFileDialog1.FileName = Listview1.SelectedItems(0).SubItems(1).Text & ".mp4"
            DialogResult = SaveFileDialog1.ShowDialog()
            If DialogResult = Windows.Forms.DialogResult.OK Then
                TCP.DownloadFileAsync(New Uri(ListView2.SelectedItems(0).SubItems(1).Text), SaveFileDialog1.FileName)


                Button1.Text = "Ferma"


            End If
        Else
            TCP.CancelAsync()


            Button1.Text = "Scarica"
            Label3.Text = ""
            Label4.Text = ""
            Label5.Text = ""
            ProgressBar1.Value = 0
        End If
        Exit Sub
Err:    MessageBox.Show("Errore! " & ErrorToString(), "Errore!", MessageBoxButtons.OK, MessageBoxIcon.Error)
    End Sub

 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Download()
    End Sub

Come posso risolvere il problema?
Grazie in anticipo