Someone explain the storage "ECRI" thing to me like I've never heard the word

Pulled operating statements on a 240-unit facility to practice on. Revenue line grows 6 percent year over year while unit count and occupancy are both flat. The broker said that's ECRI and moved on like I'd know what that meant.

So I worked backward. If doors and occupancy don't move and revenue does, it's rate. Existing customers paying more. The rent roll confirms it, tenants who moved in 2022 are paying about 19 percent more now than their move-in rate, and there are three or four increase dates visible per tenant.

What I don't understand is the limits. Can you do that every six months forever? Is there a point where the tenant walks and you've traded a filled unit for a vacant one plus a cleanup? The statement shows move-outs at roughly 4.5 percent of units per month, which I have no baseline for.

And if the whole revenue growth story on a facility is rate increases on a captive base, what happens to that story when the next buyer has already had the increases taken? I feel like I'm being shown the last owner's work rather than something I get to repeat.

Still early. Mostly want to know whether 4.5 percent monthly move-out is normal or alarming.