''It Takes a Nation of Millions to Hold Us Back''

''We estimated lifetime prevalence of psychedelic use (lysergic acid diethylamide (LSD), psilocybin (magic mushrooms), mescaline, and peyote) by age category using data from a 2010 US population survey of 57,873 individuals aged 12 years and older. There were approximately 32 million lifetime psychedelic users in the US in 2010; including 17% of people aged 21 to 64 years (22% of males and 12% of females). Rate of lifetime psychedelic use was greatest among people aged 30 to 34 (total 20%, including 26% of males and 15% of females).''
''...(A)pproximately 32 million lifetime psychedelic users in the US...'' - That is about 7 million more people than the current population of Australia, 24 million.

Over 30 million psychedelic users in the United States. (F1000 Research, 2013)

https://archive.org/details/pubmed-PMC3917651