Lloyd Johnston reports that he and his colleagues at Monitoring the Future found that last year about 5% of college students used marijuana almost every day. He says: “In other words, one in every 20 college students was smoking pot on a daily or near-daily basis in 2013, including one in every 11 males and one in every 34 females. To put this into a longer-term perspective, from 1990 to 1994, fewer than one in 50 college students used marijuana that frequently.”

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