If you have 10 rentals that have all successfully collected for 1 year that is 120 months of straight occupancy!

Another option is to split the cost based on the number of occupants in each unit but this also means you'll need to adjust the charges as tenants move in/out, so it requires more work and I wouldn't recommend it.

What is the overall occupancy for similar units in the local area?

@Adri Jusczak My thought was to have the lease drafted in the 1st applicants name only with the 2nd applicant as an occupant in the property so even if they split the lease is with 1st applicant and he will have to pay rent no matter what.What are your thoughts on that?

Any damage caused by improper maintenance of the appliance or its malfunction will be repaired by the Landlord at the undersigned Tenant(s) expense.Tenant’s clothes washer and dryer will only be used by the legal occupants of the rental unit (as determined by the signed Lease Agreement, referenced above).

I've asked about occupancy rate but wasn't able to get a solid answer.  

To add to the valuable advice provided by Kyle regarding Fair Housing issues some states also limit the amount of security deposit you can collect regardless of occupants or other factors.

In California, an accepted occupancy limit is 2 occupants per bedroom + 1 (where an occupant includes adults, seniors and children).

(any "support" dogs require documentation) No cats allowed.All occupants age 18 or more must complete an application and background check.

Poconos are great if you don't mind abysmally low 20-25% annual occupancy rates, your property sitting vacant most of the year, super high expenses, totally unreliable cleaners & handymen (ever heard of the Pocono Promise?