Help With Top 10 in Pivot Table Using Calculated Difference

I have a pivot table where I am calculating the difference in accounts from one year to another. I am trying to only show the top 10 values, but it is not giving me what I am looking for...not really sure what the logic is.

This is what I should get:

ADMITTING PM SERVICE CARDIOLOGY
MONTH (Multiple Items)

Count of ACCOUNT NUMBER2 Column Labels
Row Labels 2011 2012
-80
-63
-57
-57
-43
-37
-36
-34
-33
-33

But this is what I am getting:

ADMITTING PM SERVICE CARDIOLOGY
MONTH (Multiple Items)

Count of ACCOUNT NUMBER2 Column Labels
Row Labels 2011 2012
-80
-63
-25
-24
-14
-10
-10
7
26
48

To be honest there is so much of it. My original data is patient accounts with attending physicians. I am counting the number of patient accounts per year per attending physician and my pivot is showing the difference in # of accounts between 2011 and 2012.