How long for Rape?

Okay so in my town we had a serial rapist on campus and it took two semesters to catch him. So, as you can imagine, he racked up quite a few victims. All college age girls that attended OU. And then one girl was in a nearby town and he actually knew her personally, and that's how he got caught. So after investigating and linking him to all the rapes on campus, he went to court. Got 40 years in prison. Some people believe that that's way too much, and others think that it's not enough. I don't remember the exact amount of girls but I know it was double digits. What do you think? How long should someone get for rape? Should the amount of victims be taken into consideration?