Back in February, we detailed how record numbers of Americans — although certainly not yet a majority — support the idea of legalizing marijuana. It turns out that there may be a simple explanation for this: an ever-increasing fraction of Americans have used pot at some point in their lifetimes. The following chart details marijuana usage rates by age as determined from a 2007 survey conducted by the Substance Abuse and Mental Health Services Administration:
The peak time for pot usage occurs at or about age 20 — a period known to most of us as “college” — before declining fairly rapidly throughout one’s 20s and then plateauing from roughly age 30 through age 50.
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