Editing the marker size of charts in excel using VB code based macro

Sub sizechangemarker()
Dim Count As Integer
For Count = 1 To 5
Worksheets(8).ChartObjects(4).Chart _
 .SeriesCollection(Count).MarkerSize = 4
Next Count
End Sub

There were 5 lines on the fourth chart in the eighth worksheet. The for loops repeats the marker size setting for each series or line.