From what I've heard at dental education conferences, above 90% ON TIME graduation for a class is good. From what I remember there are very few schools that have 100% out ON TIME. Think about it, our deadline was June 15th for on time graduation at SC. Some students may be a week away from getting done, so it was maybe 11-13 students that didn't make it out by the deadline.
A school can only do so much for its students, you still have to be the one to complete your requirements, get stuff signed, pay your dues, etc, to get out on time. I would say that nearly 91% of the class being done on time is great. I would venture to bet that another 6-9 students will probably finish with in the next few weeks, and then there will be those 3-4 students that linger for a while.