Creating New Folder via Macro

Hello all,
I found the script below and it creates a folder on Drive C based on the range B9 to B54.

     Dim R As Range
     Dim RootFolder As String

     RootFolder = "C:\XXX\ABCDE\"
     For Each R In Range("B9:B54")
         If Len(R.Text) > 0 Then
             On Error Resume Next
             MkDir RootFolder & "\" & R.Text
             On Error GoTo 0
         End If
     Next R
 End Sub

Can you help me tweak the script so that it reads from B9 all the way to the last line of the column(B)?
Thank you in advance.

See how this works.

 Dim R As Range
     Dim RootFolder As String
     Dim lr As Long
     lr = Cells(Rows.Count, "B").End(xlUp).Row

     RootFolder = "C:\XXX\ABCDE\"
     For Each R In Range("B9:B" & lr)
         If Len(R.Text) > 0 Then
             On Error Resume Next
             MkDir RootFolder & "\" & R.Text
             On Error GoTo 0
         End If
     Next R
 End Sub