I have some not so detailed stats. The academy I've been with started in 2004. We've had well over 2500 people come in and try at least 1 class. As for those that signed up that percentage is lower and that works out to about 1400 people that have signed up and done over 1 month of BJJ. Of all the people that have trained with us for over 12 months at any time that I've been able to keep track of (even those that have left our academy) 7 of those people are black belts now. Another 5 are brown belts that I'm sure will eventually be black belts. There are 48 purple belts that I can remember training with us at one time or another, and I'm sure I missed some. Of those I know of 4 that definitely won't be training BJJ any more and 3 more where it seems likely they'll quit before getting to black belt. The rest I expect to one day get their black belts. There are roughly 140 blue belts ever from what stats I could gather that have been handed out by our instructors over the almost 10 years. So to the best of my knowledge at my academy the stats look like this: Black Belt: 0.5% Brown Belt and Up: 0.85% Purple Belt and Up: 4.3% Blue Belt and Up: 10% White Belt drop out rate: 90% Based off of 1400 students that did BJJ at least 1 month AND trained with us for at least 12 months. Granted, these are very imperfect stats, done from memory data from our billing system that we didn't always use. Also, take in to account people that have left the academy, some of whom might have resumed training, and for the most part this does not include people that have come to our academy from other academies that were already blue and purple belts. So take it with a grain of salt - also realize that I based the numbers off the roughly 1400 students that stayed at least 1 month that we were able to bill for at least 1 month at any time. The actual people that 'tried' BJJ is well in to the 2500 range. I'm also not including children.