Success Academy had 315 Kindergarteners in 2008. The graduating class of 2021 had 110 students. Without this new data, it would seem that their persistence rate is about 35%. But this new data I received shows that only 69 of the graduating class had started with the school as kindergarteners. So a more accurate estimate is 69/315=22% which is a little lower than the 25% I had originally estimated.