Pivot Table Difference Columns
 

I have searched but haven't found the answer. I have a pivot table with 2 columns 2007 and 2008. I want a column to show the difference between the two. I have added the sum of amount to the Values field. set up the difference. Everything works perfectly except that I get a column for the difference between 2007 and 2007 as well as the 2007 and 2008. How do I remove the 2007 column in the pivot table? My table actually has quite a few columns each with 2007 and 2008 so manually removing them is not an option.

Thanks for any help.