The UN Office on Drugs and Crime released its annual World Drug Report this month, detailing the prevailing trends in global drug cultivation, trafficking, and use.
Relying on surveys and other data, the UN estimated that 1 in 20 adults — a quarter-billion people between the ages of 15 and 64 around the world — used at least one drug in 2014.
That number, the UN notes, doesn't appear to have grown relative to the global population over the last four years, but more than 29 million of them are believed to suffer drug-use disorders.
While cocaine cultivation and demand are always in a state of flux, the UN's research into global cocaine production and consumption suggests that the world's cocaine trade is in decline.
While global coca-bush cultivation jumped 10% between 2013 and 2014, the area under cultivation in 2014 was the second-smallest amount since the 1980s. Global coca-bush cultivation was also 40% lower than the peak level reached in 2000.
RELATED: Images of Peruvian cocaine couriers
Peru Cocaine Couriers
Peru Cocaine Couriers
In this Feb. 28, 2015 photo, a patrol of elite DIRANDRO counternarcotics police walks through a puna in Husnay, Peru, after an unsuccessful mission to try to arrest drug-toting backpackers coming from the worldâs No. 1 cocaine-producing region. Its commander, Maj. Juan Tardio, said the unit spotted 15 backpackers less then a mile away early that morning but the smugglers were too far away to capture. His patrol had good intelligence, he said, but chose the wrong path of three options. (AP Photo/Frank Bajak)
In this March 16, 2015 photo, Jhorlis Huallpa, 17, carries a bagful of tarps, to be used for drying coca leaves, in La Mar, province of Ayacucho, Peru. Hauling cocaine out of the valley is about the only way to earn decent cash in this economically depressed region where a farmhand earns less than $10 a day. Beyond extinguishing young lives, the practice has packed Peruâs highland prisons with backpackers while their bosses evade incarceration. (AP Photo/Rodrigo Abd)t
In this March 16, 2015 photo, a young man dances under a heavy rain during a concert by huayno singer Ely Corazon, in La Mar, province of Ayacucho, Peru. The average cocaine backpacker, or mochilero, is typically recruited by relatives and friends - often at festivities where liquor flows. They tend not to tell their parents, who nearly always disapprove. (AP Photo/Rodrigo Abd)
In this March 13, 2015 photo, Donato fries an egg over an open fire to add to his breakfast of rice and plantain, before starting his work day of weeding coca fields, in La Mar, province of Ayacucho, Peru. Roughly one third of the 305 metric tons of cocaine that the U.S. government estimates Peru produces each year travels by foot by way of cocaine backpackers or mochileros, as they are known locally. (AP Photo/Rodrigo Abd)t
In this March 15, 2015 photo, Julio and Rufina Galvez pose for a picture holding a portrait of their late son Yuri, outside their home, in La Mar province of Ayacucho, Peru. The 25-year-old university student had gotten his fatherâs permission to haul coca in a backpack to pay for his agronomy studies, his mother said. Yuri was found face-up on a mountain trail, with bullet wounds to his head, stomach and arm, in a March 2013 cocaine smuggling trip. (AP Photo/Rodrigo Abd)t
In this March 15, 2015 photo, huayno singer Nanda la Dulce performs during a multi-village soccer tournament, in La Mar, province of Ayacucho, Peru, located in the remote Apurimac, Ene and Mantaro river valley, where 60 percent of Peruâs cocaine originates there. Huayno traditional Andean folk music. (AP Photo/Rodrigo Abd)t
In this March 13, 2015 photo, a seedling grows next to a barefooted Donato Mosco, as he weeds a coca field, in La Mar, province of Ayacucho, Peru. Peru overtook Colombia in 2012 as the worldâs No. 1 cocaine-producing nation. (AP Photo/Rodrigo Abd)t
In this March 13, 2015 photo, coca farmer Alfredo Mosco, 44, right, instructs his young employee Donato Mosco, during the weeding of a coca field, in La Mar, province of Ayacucho, Peru. Hauling cocaine out of the remote valley is about the only way to earn decent cash in this economically depressed region where a farmhand earns less than $10 a day. (AP Photo/Rodrigo Abd)
In this March 15, 2015 photo, young men compete in a multi-village soccer tournament, in La Mar, province of Ayacucho, Peru. A hardy lot, cocaine backpackers are mostly native Quechua speakers and hail from the isolated communities that suffered the worst atrocities of Peruâs 1980-2000 dirty war with Shining Path rebels. (AP Photo/Rodrigo Abd)t
In this March 15, 2015 photo, Fortunato Farfan laughs while posing for a photo in La Mar, province of Ayacucho, Peru. Fortunato is wearing a T-shirt with a phrase that reads in Spanish; "No to coca eradication in the VRAEM." VRAEM is the acronym for Valley of the Apurimac, Ene and Mantaro rivers, where sixty percent of Peruâs cocaine originates. (AP Photo/Rodrigo Abd)t
In this March 13, 2015 photo, Yohan, 4, from left, Cristian, 7, and Angelo, 6, playfully toss coca leaves into the air, singing: "I have a lot of money, look at all the money I have," in La Mar, province of Ayacucho, Peru. Hauling cocaine out of the remote valley is about the only way to earn decent cash in this region where a farmhand earns less than $10 a day. Beyond extinguishing young lives, the practice has packed Peruâs highland prisons with cocaine backpackers while their bosses evade incarceration. (AP Photo/Rodrigo Abd)
In this Feb. 28, 2015 photo, an elite policeman of the DIRANDRO counternarcotics police agency walks through a puna in Husnay, Peru, after an unsuccessful mission to try to arrest drug-toting backpackers hiking up from the worldâs No. 1 cocaine-producing region. The backpackers can choose from myriad routes in a half dozen corridors of sparsely populated steppe. They often hike at night, to avoid detection. Few know before they are arrested that they face eight- to 15-year prison sentences. (AP Photo/Frank Bajak)t
In this March 13, 2015 photo, coca farmer Alfredo Mosco, 44, who had polished off a bottle of cane liquor by midday, sleeps in his field of coca seedlings, in La Mar, province of Ayacucho, Peru. Mosco is a small coca farmer who provides work for young villagers. (AP Photo/Rodrigo Abd)t
In this March 15, 2015 photo, Rufina Galvez blows into a cane reed to stoke a fire while preparing a special chicken broth to mark the second anniversary of her son's death, in La Mar, province of Ayacucho, Peru. He adored her, ferrying her around Ayacucho on his blue motorcycle, buying her groceries, making sure she always had cell phone minutes, she said. Her son, a university student, had gotten his fatherâs permission to haul coca to pay for his agronomy studies. In March 2013, her son was found face-up on a mountain trail, with bullet wounds to his head, stomach and arm. (AP Photo/Rodrigo Abd)
This March 16, 2015 photo, a rural road is seen in La Mar, province of Ayacucho, Peru. While authorities say most of the drugs in the region are now flown out, backpacking is dependable in the rainy season, cheaper than hiring a pilot and plane - and key to evading police checkpoints. Backpackers, or âmochileros,â (âmochilaâ is Spanish for backpack), have been hauling cocaine this way for nearly two decades. (AP Photo/Rodrigo Abd)
In this March 15, 2015 photo, Rufina Galvez plucks a chicken in preparation for a special dinner to mark the second anniversary of her son's death, in La Mar, province of Ayacucho, Peru. Yuri, a cocaine backpacker, always checked in by phone she said. So when he didnât call after a March 2013 smuggling trip, his mother turned to reading coca leaves to try to divine his fate, tossing them on her skirt as is customary. âThe leaves fell spine-up, a bad sign,â she said. (AP Photo/Rodrigo Abd)
This March 15, 2015 photo shows steaming bowls of chicken soup on a table set for a special meal marking the second death anniversary of cocaine backpacker Yuri Galvez, in La Mar, province of Ayacucho, Peru. Galvez, 25, was found dead two years earlier after a smuggling trip with other backpackers. (AP Photo/Rodrigo Abd)
In this March 13, 2015 photo, Donato, from left, Delfin, and Jony, eat breakfast before starting their work day of weeding coca fields, in La Mar, province of Ayacucho, Peru. Peruâs cocaine trade is highly decentralized, run by scores of extended families who sell to representatives of foreign cartels. (AP Photo/Rodrigo Abd)
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The Andean subregion continues to be cocaine's major production area. In 2014, the total area under coca-bush cultivation in Colombia amounted to 52% of the global total, and while Colombia has seen a 58% decline in coca-bush cultivation since 2000, it spiked 44% in 2014, and that increase likely continued into 2015 (growing 42.5%, according to the White House).
UN World Drug Report 2016
In Peru, coca-bush cultivation jumped 44% between 2000 and 2011. While cultivation fell 31% between 2011 and 2014 (back to 2000 levels), it still accounts for 32% of global coca-bush cultivation.
Bolivia's coca-bush cultivation has yo-yoed, falling in the 1990s, doubling between 2000 and 2010, and falling 34% between 2010 and 2014. In 2014, it had 15% of the world's coca-bush cultivation — half the total area under cultivation during the 1990-1997 period, but 40% more than in 2000.
All in all, however, when global cocaine seizures are subtracted from production estimates — and shifting market patterns and user habits are taken into account — the result is "significantly less cocaine on the market," Insight Crime noted.
The UN's estimate of the world's opiate users — that is, users of opium, morphine, and/or heroin — has remained stable in recent years and was believed to be about 17 million people in 2014.
UN World Drug Report 2016
Because of high opium-production levels in the past, the UN doesn't expect the decline of opium production in 2015 — down 38% from 2014 — to cause major shortages on a global level. That drop in production was driven by a 48% fall in opium production in Afghanistan's southern provinces, though the country still had nearly two-thirds of the world's area under illicit opium cultivation.
Regionally, heroin consumption appears to be increasing in North America, causing a spike in heroin-related deaths, while Western and Central Europe have seen stable or declining heroin-use rates since the 1990s, though there are signs that the market in Europe is growing.
Heroin trafficking, however, seems to have increased around the world, with the "Balkan route" — a conduit for Afghan opium through Iran and Turkey and into Europe via the Balkan states — continuing to be one of the most important routes. Iran accounted for the largest aggregate opiates seizures in 2014, including 17% of global heroin seizures.
Heroin trafficking in the Americas has increased in line with production increases in the region over the last 20 years, as well.
"Since 2009, global amphetamine seizures have fluctuated annually between about 20 and 46 tons," the UN reported, and methamphetamine has been "particularly dominant" among amphetamine-type stimulants (ATS) seized in East Asia, Southeast Asia, and North America.
UN World Drug Report 2016
North America has consistently reported the most seizures of meth, and between 2009 and 2014 seizures of the drug in East and Southeast Asia nearly quadrupled, according to the UN.
Worldwide, seizures of meth were up 21%, amounting to 108 metric tons.
Between 1998 and 2014, seizures of amphetamine-type stimulants outstripped seizures of other illicit drugs. While the total seized has ebbed and flowed over that time, in 2014 reported seizures of ATS were nearly eight times more than was reported in 1998.
The UN also reported that between March 2014 and November 2015, significant amounts of amphetamine tablets labeled "Captagon" were reportedly intercepted in the Middle East. The report noted that while Captagon trade was mainly interregional (two tons of it were seized in Beirut before being loaded on a Saudi prince's jet in October 2015), large amounts had reportedly been moved from Lebanon and Syria to places outside the region.
Those seizures would seem to back reports that Captagon production had spiked in Syria since that country's descent into civil war in 2011, with unconfirmed reports of various factions in the country using sales of the drug to fund their operations.