I’m not suggesting they these numbers are in contradiction. I believe they are actually measuring any time enrollment in that period. Otherwise the statistic s

I’m not suggesting they these numbers are in contradiction. I believe they are actually measuring any time enrollment in that period. Otherwise the statistic seems of little value. On time high school graduation is achieved by around 86% of the population. This surely accounts for much of the difference. https://nces.ed.gov/fastfacts/display.asp?id=805 https://nces.ed.gov/fastfacts/display.asp?id=805