Global Prevalence of Cannabis Use
"Cannabis use has increased globally, particularly in Asia since 2009. Although epidemiological data is not available, experts from the region report a perceived increase in use. The regions with a prevalence of cannabis use that is higher than the global average continue to be West and Central Africa (12.4 per cent), Oceania (essentially Australia and New Zealand, 10.9 per cent), North America (10.7 per cent) and Western and Central Europe (7.6 per cent). Cannabis use in North America and in most parts of Western and Central Europe is considered to be stable or declining."
UNODC, World Drug Report 2013 (United Nations publication, Sales No. E.13.XI.6), p. 1.