Should I count on garage rent?

[Jaston Robinson]

Hi bigger pockets. I was recently pre-approved to buy a 3 family via FHA. I'm interested in buying and holding investing. Here's the numbers.

Asking: 399k 

Down payment 3.5%: 13.9k

Garage income annually: 8.4k

Rent income annually: 37.k

I wanted to get some advice on the garage income. There's 7 garages which all rent for $100 per month totaling $700 per month & $8.4k annually. Should I count on this income? What are some of your experiences with garage renters? Are these leases usually month to month? Thanks in advance!