There aren't statistics, but I can tell you anecdotally that, absolutely, there are extreme differences in that. One of the concerns, of course, with delta-9 THC is that it's ephemeral. I'm grossly oversimplifying it, but let's just say delta-9 dissipates from the blood very quickly.
Here in the state of Nevada, about 78% of the population lives in Las Vegas, another 17% lives in Reno, and the seventh largest state in the United States has the other 4% living everywhere else. There are huge swaths of land separating things. We have two counties in Nevada that don't have hospitals, so to get a blood sample in some instances, the closest location is 200 miles away.
We also have limitations on that. For law enforcement to even have the ability to collect blood is a challenge, and I definitely foresee that happening in Canada as well.