Where does the £6b number come from? It seems very high to me. A 2014 survey has the following numbers: 31% have ever used illegal drugs, 21% still take illega

Where does the £6b number come from? It seems very high to me. A 2014 survey has the following numbers: 31% have ever used illegal drugs, 21% still take illegal drugs "even if only occasionally". 93% of people who have tried illegal drugs have tried weed. [1] Let's say the UK population is 65 million, that makes 13.65m "occasional or more often" illegal drug users, and if we assume that all of the 93% of those who have tried weed still smoke weed, that's 12,694,500 weed smokers. So with that number, to hit a total spend of £6B they would be spending an average of £472 each, or £9/week - I guess that's about 0.5-1g/week. I could believe that amount as an average among "weed smokers", but given the number includes people who say they do it "only occasionally", I suspect the long-tail means that £6b is unrealistically high. That said, if you have a source for that I'd be interested to see more info. [1] http://www.theguardian.com/society/2014/oct/05/-sp-drug-use-is-rising-in-the-uk-but-were-not-addicted http://www.theguardian.com/society/2014/oct/05/-sp-drug-use-...