You're right, and I should have added a disclaimer that the numbers are more relevant to dropping out of a stream (or needing to take something but choosing not to continue further), rather than a explicitly dropping out of a major.The large difference in attendance is probably not due dropouts though. E.g. plenty of people who need to take 1st year math aren't math majors, but are likely to be from engineering or other science majors. It's pretty difficult to infer the dropout rate of a degree, unless you have some degree-specific courses in your first year that nobody from other faculties would take. E.g. for me, we had a first year aerospace engineering course, which only aerospace engineering students would take, so we could see everyone who was in that degree, and then compare to the attendance of the core 2nd,3rd,4th year aerospace courses. But even then, you have people doing combined degrees, or people who do part-time uni, so there will be a difference in attendance simply due to a difference in their plan of study. All in all, I think it's pretty hard to guess the dropout rate unless you ask your course coordinator or something lol.