Our averages were always around low to mid 70's in our pharmacology/therapeutics type classes. Some lower, some higher depending on the material and the professor. I think there were a few people that consistently aced the exams and a few that consistently flunked, but most were right down the middle.
Average for PDAT courses, Pharmacology and therapeutics courses, have run from a low of about 60% to a high of 83%. Overall, I have to say the average is somewhere in the low to mid 70s. Average grade is normally the cut off between a B and a C.