10. Magic Mushrooms (10.6 %)(01 of10)
Open Image ModalMushrooms for sale are displayed in the smartshop Innerspace in Amsterdam 18 October 2007. (MAARTJE BLIJDENSTEIN/AFP/Getty Images) (credit:Getty)
9. Amphetamines (11.7 %)(02 of10)
Open Image ModalA variety of crystal meth equipment that were confiscated as part of Operation Slab at the North Shore Policing Centre on August 19, 2010 in Auckland, New Zealand. (Photo by Phil Walter/Getty Images) (credit:Getty)
8. Electronic Cigarettes (12.3 %)(03 of10)
Open Image ModalIn this photo illustration a woman holds an e-cigarette on April 2, 2014 in London, England. (Photo by Peter Macdiarmid/Getty Images) (credit:Getty)
7. Cocaine (16.4 %)(04 of10)
Open Image ModalIn this Jan. 26, 2014 photo, a bag of cocaine that was found in the baggage of Liz Rabines, from Spain, sits on a scale at the anti-narcotics police station inside the Jorge Chavez International Airport in Lima, Peru. (AP Photo/Martin Mejia) (credit:AP)
6. Shisha Tobacco (18.5 %)(05 of10)
Open Image ModalAn Egyptian man smokes a water pipe, known locally as Shisha, in central Cairo on December 15, 2012. (MARCO LONGARI/AFP/Getty Images) (credit:Getty)
5. MDMA (23.4 %)(06 of10)
Open Image ModalA mock 'ecstasy' lab for teaching purposes at the new National Clandestine Laboratory Training and Research Facility December 5, 2008 at the DEA Training Academy in Quantico, Virginia. (TIM SLOAN/AFP/Getty Images) (credit:Getty)
4. Caffeinated Energy Drinks (45.9 %)(07 of10)
Open Image ModalIn this photo taken Wednesday Sept. 28, 2011, a student's can of Red Bull energy drink is seen on a table at the student union building at the University of New Hampshire in Durham, N.H. (AP Photo/Holly Ramer) (credit:AP)
3. Cannabis (48.2 %)(08 of10)
Open Image ModalThis Feb. 1, 2011 file photo shows medical marijuana clone plants at a medical marijuana dispensary in Oakland, Calif. (AP Photo/Jeff Chiu, File) (credit:AP)
2. Tobacco (56.7 %)(09 of10)
Open Image ModalIn front of the backdrop of the barn in which the burley will be stored, a group of farm workers makes their way across a tobacco field hoeing weeds out of the rows in the early morning Monday, July 11, 2011, near Sparta, Ky. (AP Photo/Ed Reinke) (credit:AP)
1. Alcohol (90.8 %)(10 of10)
Open Image ModalIn this Dec. 5, 2011 file photo, bottles of Jack Daniel's Tennessee Whiskey, line the shelves of a liquor outlet, in Montpelier, Vt. (AP Photo/Toby Talbot, File) (credit:AP)