Somewhere between zero and one. I have a friend who has been using the M9 for years and will get one at some point, but he's out traveling somewhere for a few months, which he does often, so I won't know until he "visits" home. Independently wealthy, and travels the world for the sake of it. It's not his camera that I envy. 😀
Otherwise I only know a few Leica users, mostly recent M and Bessa film, one who has her grandfather's Leica II or III in storage, and only one M8 in the digital camp.
Cheers,
Rob