Since almost all the production and trade in these drugs is illegal, statistics
are notoriously unreliable. The largest exporter of cocaine is probably Colombia,
followed by Peru and Bolivia, while Myanmar seems to be the leading
source of heroin. Pakistan is one of the major exporters of cannabis. One study
of the nine major producing countries estimated their annual production ofcocaine
at around 300 tons, heroin at around 250 tons and cannabis at well
over 25,000 tons.