I saved all the papers used for tests, homework, reviews, etc. for my bachelor's degree in Physics. I wanted to know how paper I had used. You see it all right there. This doesn't include scratch paper. That would have been at least another 25% more paper. Maybe significantly more.
I looked up that a "typical" tree yields 8333 pages of letter paper*. That means 8/10 of a tree was consumed for my undergraduate education.
There you go: