For the Americans who are confused by this strange Canadian phenomena!....
In almost all of Canada, you are done high school after grade 12.
Then, after grade 12, you can enter university (provided you have decent grades, of course

).
HOWEVER.......In the province of Ontario, for many years, they also had Grade 13. (Don't ask me why...I am a British Columbian and my Toronto friends tried to explain it to me and I would zone out by the 3rd sentence)
Grade 13 has now been phased out. From here on in, kids will graduate after Grade 12, not Grade 13. However, you still have that
last gasp of kids in Grade 13, the last ever grad class of Grade 13'ers.
So for this one year, universities are having kids coming from Grade 12
AND Grade 13, so you have twice as many kids ready to start university at once, hence the problem with space.
This is what is being discussed, and most of the Canadians on this specific thread are from Ontario (Toronto, Ottawa and Guelph) ....
Hope that cleared it up!
P.S. Grade 13 = OAC, which stands for Ontario Academic Credit...
I think