Is this what you are looking for?
I used the instructions on the below link to create the difference subtotal:
The formula for the difference calculations looks like this:
IF FIRST() = LAST() THEN
SUM([ELA Percent A's & B's])
( LOOKUP( SUM( [ELA Percent A's & B's] ) , LAST() ) - LOOKUP( SUM( [ELA Percent A's & B's] ) , FIRST() ) ) , NULL )
I also turned on subtotals, instead of the grand totals as the above link shows, and computed both calculations with Endyear (copy).
It may be a bit complicated, so let me know if you need any clarification.
Sample_reshaped.twbx 45.7 KB
Joshua, this is EXACTLY what I've been striving for and I sincerely appreciate not only your solution, but the full explanation and link as well!
Thank you SO much!