I have seen the NWL stats somewwhere, just can't remember where, I think it was about 50 on avg that come off the list. However, I don't know if that number is included in the offered appt pile when they do the break down or not.
I would also assume that a higher amount is given to ROTC over JROTC, since many of the candidates that are ROTC were also JROTC in hs. Also, many ROTC students have gone through the process before and now know their exact weaknesses, so they make sure that they fill in those areas (i.e. they had a low CFA, or low ECS). They also have all college classes, which means their gpa would be rescored higher than the hs, increasing their PAR. Their ALO would be a new ALO, but aware of the fact that they are trying again. The ALO may rack and stack thm higher than the hs student just based on the fact that this candidate has shown their dedication to get to the AFA. They just didn't say "oh well, I didn't get an appt, o I'll be commissioned via ROTC, no biggie" instead they said I am not giving up, I will put myself through this all over again. Finally, one of their recs will be their det commander, I would assume that the board would give more weight to det commander who is in charge of cadets that actually receive commissions, than the hs commander where many kids take JROTC as an elective to fill their course schedule. ROTC cadets carry extra courses because ROTC is not a class that can be assigned as an elective in college. These kids as freshman only get 1 credit per semester, but they still have mandatory pt 2 x a week, plus mandatory volunteer hours (yes, I know that is a paradox...mandatory and volunteer).
The ROTC student probably has one more thing in their file that the JROTC does not, and that is the PQFT and if they score high, that shows their abilities regarding the AF. It can work against them if they are low too! This is a test that is administered in October to ROTC and AFA cadets. The only equivalent I could give it is the SAT for the military. Score low and you can kiss UPT buh bye even with the best eyesight. The higher scores are usually cadets that have PPL hours since they understand things like air speed and alt. I think when Bullet was in ROTC he scored 89,(never being in a cockpit) but later on in his life when he thought of x training from WSO to pilot he had to do it again, and then he had a 99.