Yes but 13,000 go to the city centre is the point.
No offence to anyone on here who has attended, but Sunderland University is pretty shit for most subjects and isn't exactly attracting the kind of students that will go out and spend money, they're all at Newcastle or Durham. A lot of Chinese students as well who for the most part don't integrate well, they stick to their own shops, their own places to socialise etc. The university campus is spread throughout the city as well, there's no city centre campus that I'm aware of?
Very few people work in the city centre, and those that do are working in retail and other low skilled (paid) roles. That's why the town is on its arse. It needs an injection of white collar workers with a few quid in their pocket who can afford to stay out after work for a few beers or a meal.