These numbers could represent an increase in use among Americans , or simply an increase in the number of people who felt OK reporting use of the drug on a national survey . About 7.3 % of Americans age 12 or older used marijuana regularly in 2012 , survey finds . Comment: Heroin use is up 70 % since 2007 , according to the survey .
About 7.3 % of Americans age 12 or older used marijuana regularly in 2012 , survey finds . Comment: Heroin use is up 70 % since 2007 , according to the survey .