Evaluating Area Vacancy Rates (Grove City, PA)

[Cory St. Esprit]

I am a restaurant franchisee w/ 28 units and I've started buying up the real estate. I'm currently looking at adding a restaurant to the portfolio, which includes the real estate. It's a main street property with the restaurant on the main floor and two one-bedroom apartments above it. It's a small college town (Grove City, PA). I had someone go up there and take a look today (I'm international for right now, but will be back to see in-person in April before making a move, if any). They said lots of apartments up there, but they thought they looked vacant. So my question is, how can I tell vacancy rates and if this would be a good deal? I know vacancy is part of the game (We have about 12 other doors, including residential and commercial)....but how do I judge whether an area just isn't getting a lot of folks renting in it? I figured a college town would be good for students.