It makes sense that there would be a higher proportion of the student body with special needs at a college as compared to a university, but 20%?  Not that I disbelieve you, but that is a shockingly high number!

Dsylexia and autism spectrum are probably big ones, and let's face it, most of those kids would not be heading to university.  It's an epidemic, as it is for young people suffering from anxiety.  Social media and smart phones are probably leading to many of the anxiety problems.