how many students are selected for the scholarships?
Scholarships don't work that way. There are lots of different types of scholarships, the amount of students selected depends on the type of scholarship. A lot of scholarships have criteria which is difficult for the average student to meet - which is kind of the point. I.e. there are a lot for indigenous students, students from disadvantaged backgrounds, in Engineering/IT there are often small scholarships for women etc.
Then there are co-op scholarships which are the biggest in terms of dollar value but the amount is not that impressive all things considered (in terms of the money, those programs offer more than that though) since you have to do work experience at the sponsor companies and the scholarship is essentially the pay for that spread over the course of your degree rather than just when you are working. (for UTS coop programs at least, i'd assume it's similar elsewhere). You'd be far too late to apply for a coop scholarship for 2014 entry.