Not strictly on topic, but fits here.

The World Drugs report for 2012 is out and it shows that 230 million people around the world - 1 in 20 of us - took illicit drugs in the last year. The report also says that problem drug users, mainly heroin - and cocaine-dependent people number about 27 million, roughly 0.6% of the world adult population. That's 1 in every 200 people. The report is published by the United Nations Office on Drugs and Crime and is full of fascinating stats - we've extracted some of the key ones for you in this visualisation, created by Andy Cotgreave of Tableau. Click on the map to see how drug use changes around the world.
Link:http://www.guardian.co.uk/news/datab...-use-map-world

Not sure whether the UNODC has the best data.