Hi Ivan Petkov,
Change the format of the cell to percentage.
But since you said that you have a dynamic range, a little bit of code could be useful.
Right-click on the sheets tab and select "view code". Paste the following code in the big white field:
Private Sub Worksheet_Change(ByVal Target As Range)
Now use the following formula and you won't have to adjust the range anymore:
Dim lRow As Integer
If Intersect(Target, Columns("F:F")) Is Nothing Then Exit Sub
lRow = Range("F1").End(xlDown).Row
ActiveWorkbook.Names.Add Name:="MyRange", RefersTo:="=$F$1:$F$" & lRow
Hope you like.