Australia and New Zealand have the highest rates of cannabis and amphetamine use in the world, according to comprehensive research on illicit drug use. Up to 15 per cent of 15 to 64 year olds in the two countries use cannabis, while 2.8 per cent of the same age group use drugs such as speed and crystal meth. The latter figure does not include use of ecstasy. The data is included in a series of papers examining global drug use and law enforcement.
Prof Louisa Degenhardt, National Drug and Alcohol Research Centre(NDARC), UNSW
The Lancet; http://newsroom.unsw.edu.au/news/health/highest-rates-cannabis-use