I am trying to create a Pivot Table to show the WOS (weeks of stock)
by week for YOY (2005, 2006 and 2007) for certain product families.

WOS = OH/AWS where OH = On Hands (available data) and AWS = Average
weekly sales (also available data). I did the WOS calculations myself
on Excel and used the data to throw it in a pivot table.


When I'm displaying an individual SKU from a certain product line of
a
certain product family my numbers are right. The problem is whenever
I
collapse it further to see the whole product line (or the whole
product family), I see a sum of my WOS for all the SKU's in that
certain category as opposed to its average.


Is there anyway to rectify this issue? Any help in this matter would
be appreicated.