taking average of 10 sample in vb2010 - vb.net

Question

I have used below code to find average of 10 sample . But during first time it take sample and do the averaging . during next cycle counter not become Zero.and text box not updating
Static counter As Integer = 0
DIm average_sum As Double = 0
If counter < 10 Then
counter = counter + 1
Count_val.Text = counter
Dim array(10) As Double
For value As Integer = 0 To counter
array(counter) = k
average_sum = average_sum + array(counter)
Next
If counter = 10 Then
average_sum = average_sum / array.Count
System.Threading.Thread.Sleep(250)
Array_count.Text = average_sum
End If
If counter > 10 Then
average_sum = 0
counter = 0
End If
End If

Answer 1

If Avg_count < 10 Then
Dim array(10) As Double
For value As Double = 0 To Avg_count
array(Avg_count) = k
average_sum = average_sum + array(Avg_count)
Avg_count = Avg_count + 1
Next
If Avg_count = 10 Then
average_sum = average_sum / Avg_count
System.Threading.Thread.Sleep(250)
Average.Text = average_sum
Avg_count = 0
End If
End If
Here count value setting properly . But after 2 to3 cycle Average will done earlier itself same thing i writen in excel to compare averages but not matching with average and excel sheet data
Below is excel sheet code.Both code are in timer1 block.
If counter < 10 Then
'counter = 0
'average_sum = 0
Dim headerText = ""
Dim csvFile As String = IO.Path.Combine(My.Application.Info.DirectoryPath, "Current.csv")
If Not IO.File.Exists((csvFile)) Then
headerText = "Date,TIME ,Current, "
End If
Using outFile = My.Computer.FileSystem.OpenTextFileWriter(csvFile, True)
If headerText.Length > 0 Then
outFile.WriteLine(headerText)
End If
Dim date1 As String = "25-10-2014"
Dim time1 As String = TimeOfDay()
Dim x As String = date1 + "," + time1 + "," + distance
outFile.Write(x)
End Using
End If
If counter > 10 Then
counter = 0
End If