It says 14% of americans smoke pot. I think that sounds accurate. That is 44 MILLION people in case you were wondering.
317,493,212 is the current population. If you discard people under 15 and over 70 you are left with the you have (219685604) that means 20% of the US smoke pot.
Pot people always like to over inflate the usage number, but 14% too funny. Even in states where its legal, it would not reach 20%.