When I sort the free agents by either 7-day or 30-day add to try to get the largest positive values to the top of the list, it returns first all the negative (drops) and then the properly sorted positive (adds) father down the page. If you reverse the search, all the zero values appear at the top of the list. Zeros are not interesting, so one sort should give you the highest positive values (most adds) and the other sort should provide the most negative values (most drops).
Not a big deal, but took me a bit to figure out what was going on so wanted to pass it on.