Select Case code not returning correct statement

This is my code which I use in conjunction with a drop-down list. The "ni" range is the output range for the drop-down box. The "n" in the case statements is the value I want associated with the "ni", and the "nval" is the output where the value for "n" goes. When I try to run this code, The value for "n" that is returned is 0. I am not very good at vba and therefore cannot find where my problem is. This is the code.

Sub Roughness()
Dim n As Integer

Select Case Range("ni")
    Case 1
        n = 0.011
    Case 2
        n = 0.012
    Case 3
        n = 0.015
    Case 4
        n = 0.022
    Case 5
        n = 0.011
    Case 6
        n = 0.03
    Case 7
        n = 0.035
    Case 8
        n = 0.04
    Case 9
        n = 0.009
    Case 10
        n = 0.01
    Case 11
        n = 0.012
    Case 12
        n = 0.011
    Case 13
        n = 0.019
End Select

Range("nval").Value = n

End Sub

I have another Select Case sub in my program that works perfectly, and has the same format as this one.