I don't know where I heard this statistic but the vast majorty of SFH rentals are owned by those who just have <2 properties (unsophisticated in a respectful sense).

People pay rent from their income, rather than from their savings.Be careful about those statistics, also.

Statistically insurance companies know older buildings have more things fail and have more claims happen.Some investors just get fire and casualty insurance which can be cheaper sometimes.

Interview a few agents and ask them statistics about their business. 

RBI statistics compiles the information.

Happy Holidays.My team and I are compiling a list of websites and data sources that we can turn to to determine whether a particular market / MSA (Metropolitan Statistical Area) is worth investing in. 

Property managers don't provide significant value-add back to owners, such as data and statistical analyses on how to increase the profitability of properties.  

I'd like to get some statistics on how good these investments actually were so I can determine if we should continue buying more houses (or even sell and get out).  

@Roman Pak, I have read statistics that say open houses lead to sales between 4 and 10% of the time.

Your goal is aggressive and I like it but be realistic....We all dream of retiring after just 8 years of investing but that's not statistically likely.