It was a smaller program (less than 40 students).   

Because I can get applicants with no credit score (such as grad student/ post docs) that is why I don't set a number.

High turnover and having the option to rent out to students or young professionals.

Because I am a full-time college student and I work part-time I ask that the interested parties submit a rental application before I show the house, but many of them refuse to give a rental application unless they can see the house first.The criteria for what I look for in a rental application are as follows:Credit report: I look to see if they have had at least 90% or higher on-time paymentsBackground check: I look to see if they have ever been evictedJob and rental references: I look for a steady income and make sure they can afford it with what they make I also call their current landlord to make sure they have been a good tenant and confirm the information the tenant gave me.I currently have it listed at $1650/month with a 12-month lease.

So apparently many insurers won't give us insurance for a property that has students (undergrads or grads) living in it.

How are summer months handled with students?

As a student of history and electoral politics, my hypothesis was a flat no, and the research did verify at least most of my assumptions.However, I could have written a book about this topic, and I really don't think I can answer the question succinctly enough in 2,500 words.

Find students that are quiet and ask them what they think.

I recommend talking to @Gino Barbaro, He coaches students to invest in Multifamily, rising money through Partnerships and Syndications. 

I started in Real Estate investing in 2013 when my daughter went to college ( first investment was student rental), i still own that house and several others in the town, not all student rentals. i look at this as my retirement in the near future and my kids inheritance should i ever pass.