Misleading Official Statistics on Interdiction and Seizures: "Comparing absolute numbers of total cocaine seizures and manufacture could be misleading. To understand the relationship between the amount of annual seizures reported by States (694 tons cocaine of unknown purity in 2010) and the estimated level of manufacture (788-1,060 tons of cocaine of 100 per cent purity), it would be necessary to take into account several factors, and the associated calculations would depend on a level of detail in seizure data that is often unavailable.
"The total quantity of heroin seized globally reached a record high in 2016, while the quantities of opium and morphine seized reached the second highest level ever reported. The largest quantities of opiates seized were of opium (658 tons), followed by seizures of heroin (91 tons) and morphine (65 tons). Overall seizures of opiates, expressed in heroin equivalents, increased by almost 50 per cent from 2015 to 2016, of which the quantity of heroin seized exceeded that of opium and morphine.
Estimated Worldwide Cocaine Seizures According to UNODC: "Data suggest that the global cocaine interception rate, based on cocaine production estimates and quantities of cocaine seized, reached a level of between 43 and 68 per cent in 2014."