Several factors could explain why the homeownership rate remains relatively high.

Writing the Contract:**It's highly advisable to consult with a real estate attorney who can draft a comprehensive contract that outlines all the terms and conditions of the seller financing arrangement.

PML are giving very high interest rates of 10% plus.

Exterior/Interior Paint, fixtures, etc.These buildings were constructed in the 1960s with steel pipes and much of the plumbing has been replaced as needed including new supply lines in the ground and new sewer pipes under the slabs.Ongoing maintenance costs have been pretty consistently high on this project, but the rise in rent over the holding time has been a saving grace.

@Wes Holmes Just to add a bit more meat to the bone of what others have said:It's standard practice for hard money lenders to require a personal guarantee, but once you have significant experience under your belt, lenders are sometimes willing to drop the requirement for a slight decrease in leverage and/or increase in rate.Regarding extra collateral, lenders sometimes ask for this if the deal is too high risk for them as-is, but you have significant equity in other properties that make it wash.

Other states are landlord friendly and have high taxes. 

I now have a ten-page agreement and it keeps me out of a lot of hot water. 

For example, if you don't like the area in terms of the rental market (ex. high crime area, rural, low cash flow, no appreciation), it would make more sense to just to flips.

The rebound came suddenly amid still very high interest rate environment.

If you can't keep control of your personal finances, you are highly unlikely to succeed in real estate investing.