Cheating in summer school?

To preface this I don't cheat because I don't learn the material if I do, but I'm comparing to my classmates during summer school and they are all like a unit ahead of me when I can barely do like 2-3 lessons a day. Idk if this is just a skill issue on my part but this makes me feel like they might be cheating. What percentage of summer school students or online students do you think cheat?