I wouldn't be too sure. I know the number of marijuana users is high (no Pun intended) but your figure is probably low.
Keeping it illegal has done more harm than good. The amount of untaxable sales isn't chump change.
But Conservatives believe it is. My late mother in law would have benefited from it during chemo, but, even if it were legal here, it had the stigma of only dopers using it.
Hell, the amount of taxes it generates in Colorado is so high that they've actually started improving their schools.