I am in Canada and I get matched with people from North America. I don't know where the numbers come from, they are just listed right on Xbox when you select a game type.
Can you take a screenshot of it? The way matchmaking works is if it can't find any games in your regional server, it automatically puts you into another server with a working lobby. So you could be looking at regional and getting put into a east/west US server. I don't think there is a canadian server though so not sure if that is why, but it's the only thing I can think of.... Unless the player base has dropped that much in 2-3 months... which would be disappointing :/
I uninstalled the game to make room for Halo and it'll take me forever to dl it again or I'd check.