"most have stopped smoking dope by the time they are 18"

The proportion of adults who have used cannabis in the last 12 months has fallen from 9.5% in 1996 to 6.6% in 2009-10 and appears to have steadied at 6.9% on the most recent 2011-12 figures.

This overall picture of illicit drug use stabilising at its lowest levels since 1996 is confirmed in new Department of Health data published on Thursday on patterns of smoking, drinking and drug use among school pupils aged 11 to 15 in England. The long-term steady decline in all three continued last year, with 140,000 regular smokers, 360,000 regular drinkers and 180,000 saying they had taken drugs in the previous month.

Read More | "Drug taking among 16- to 24-year-olds at lowest level since 1996" | Alan Travis | ?The Guardian