This is how my students did in Physics 1 and AP Physics 2 in the first semester of the 2010-11 academic year.
Physics 1 (N = 123): there was a 68% "Advanced and Proficient" (A and B) rate. I always hope for 75% A's and B's. Sixty-eight percent isn't bad. By my own recollection, it's the best my Physics 1 students have done in recent years. There was also a 14% D-F rate. I've never been able to drive that down to zero, though I have had years when there were no F's at all.
AP Physics 2 (N = 21): there was a 67% A-B rate and a 14% D-F rate. In fairness, that was really a 14% D rate, since thee were no F's. The A-B and D-F rates of AP Physics 2 and Physics 1 don't usually track so closely. The material in AP is significantly more challenging, but the students tend to be the school's top math/science students.
I don't have much deep analysis to make here; this is simply a snapshot of "Rio physics that was."