According to the Census, there are 137,657 housing units occupied by renters in the District (note: not rental housing units, of which there are presumably more). And according to a report out today from the Urban Institute, 79,145 of those spread out over 4,818 properties are “potentially subject to rent control”—-that is, built before 1978, composed of five or more units, and not claiming any of a handful of exemptions available to them. The authors emphasize that it’s not a perfect inventory, city records being what they are.

The report proceeds to break down that number by ward, type of ownership, size, and other criteria. It doesn’t, however, tell us anything about the quality of those rent-controlled apartment buildings: How full they are, whether their owners are adhering to regulations, and how many petitions they’ve filed to raise rents beyond otherwise allowable levels. It also doesn’t give us any idea how fast the stock of stabilized units is declining.

But it’s a start. And there’s this nifty map: