Phone UCT and see if they have any research material on the subject.
But my guess is 50% porn, 25% party sites, 20% forums & chat sites with a full 5% to do with research and study.
Everyone at our University (TUKS) everyone past 1st year knows how to use the Internet and I'm sure plenty do. We have 2 compulsory computer literacy courses (one of which can be exempted by writing a test.) which deals heavily with using the internet and searching the internet.
I see people use the internet on campus all day(aka the Open Labs are full and the IT labs are pretty close to full as well) so I'd say at least 50% of the students use Internet but phone the campuses and ask if they'd share that info.
Our campus PC's block porn and all sorts of other things which is why Foxyproxy exists
heh uct started a quota system but since i use at home, an i bypass their authentication proxy thingie mine is still at 0 except on days when i am lazy :/ so total for last yr was like 30 MB