Current role of F-16s in USAF (continuation)

I was reading the current issue of Air Forces magazine and got the scoop on the F-16s in the USAF, goes as follows;

1 F-16A Block 15
197 F-16C/D Block 25
350 F-16C/D Block 30
51 F-16C/D Block 32
222 F-16C/D Block 40
174 F-16C/D Block 42
198 F-16C/D Block 50
52 F-16C/D Block 52

Active duty 701 (2007) 646 (2012)
Air Gaurd 490 (2007) 381 (2012)
AF Reserve 54 (2007) 59 (2012)?
Totals: 1,245 (2007) 1,086 (2012)

my only query is regarding the F-16A Block 15, would it simply be an agressor aircraft?