REITs started booming after 1992, which probably dramatically increased the scale of corporate landlording, along with the improving rental management tooling/software that is making it increasingly easier to manipulate the rental prices and push it upwards.
What did you select 1992? What is particular about that year. And do you really think property managers had sophisticated software to adjust rents in 1992? Computers in 1992 were pathetic. I guess you could use Lotus 1-2-3 from DOS.