Crushed rhino-horn powder can sell for as much as $25,000 per pound on the black market.

DLILLC/Corbis

n underground markets, rhino horns are now worth an estimated $25,000 per pound, more than the cost of the same amount of cocaine in the U.S. In countries like Vietnam and China, people use the ground up horns, which produce a fingernail-like substance, to treat everything from headaches to fevers and even cancer. Although the medicinal benefits of the horns are scientifically unproven, illegal poaching of the burly animal hit an all-time high in 2011: In South Africa alone, where 90 percent of the world's rhino population lives, 448 of the mammals were killed last year. The death toll is expected to climb even higher in 2012. Authorities have tried to curb the trend by pre-emptively removing the animals' valuable horns, but poachers are still killing de-horned rhinos to cash in on the nubs. Here's a look at the violent surge, by the numbers:

28,000
Rhinos remaining worldwide

13
Rhinos killed in South Africa in 2007

233
Rhinos killed in South Africa in 2010

448
Rhinos killed in South Africa in 2011, an all-time high

160
Rhinos killed in South Africa since January 2012, already outpacing the 2011 rate

95
Killings in South Africa's Kruger National Park, accounting for roughly 60 percent of rhino deaths so far this year

$25,000
Estimated cost per pound of crushed rhino horn powder, "making the hoof-like substance literally as valuable as gold," says Mike Ives at the Associated Press. The highest demand comes from China and Vietnam. In Vietnam in particular, rhino horn "has become a must-have luxury item for some Vietnamese nouveau riche, alongside Gucci bags and Maybach cars."

$8,000 to $16,000
Estimated cost per pound of cocaine in the United States

$10
Cost for a small prescription of rhino horn from a medicine dealer in Hanoi; some doctors say the substance can cause rashes

1
Proteins composing a rhino's horn. Unlike the bony protrusions of other animals, "rhino horns are keratin all the way through," says PBS. The purported medicinal properties of the horns, which were shown to slightly lower the fever of rats in a 1990 study, can theoretically be achieved "just as well by chewing on your fingernails."

72
Rhino horns stolen from 15 European countries in 2011, according to the law enforcement agency Europol. Thieves "are now pinching rhino horns from European museums and taxidermy shops, sometimes smashing them with sledgehammers before fleeing," says Ives.

60 to 100
Legal trophy horns transported from South African game farms to Vietnam annually

3
Vietnamese diplomats caught in illegal rhino horn trafficking scandals between 2006 and 2008

4
White rhinos currently being kept in captivity at a zoo outside the city of Hanoi to protect them from poachers. Even though the zoo has 24-hour security, the zoo's manager is still fearful thieves will kill the animals.

0
Wild rhinos remaining in Vietnam. The last known rhino in the country was found dead with its horns hacked off in 2010.

Sources: Associated Press, Mother Nature Network, MSNBC, PBS, U.S. Drug Trends