This is what the DEA had to say about marijuana consumption in Delaware in 2008:
Adults remain the predominant users of marijuana, especially in large social gatherings, such as rock concerts. Reports indicate that marijuana is typically smoked in combination with crack cocaine, heroin, and PCP.
In my book, "typically" means "most of the time," or close to it. Also – "rock concerts"? Seriously?
Update: I also found another doozy in the DEA's 2008 California summary. In the prescription drugs section, it says "Rohypnol is rarely encountered by law enforcement within in the greater Los Angeles area," but then a couple paragraphs later, in the other drugs section, it says "Vicodin, Ritalin, Rohypnol, Ketamine, and Valium are commonly diverted pharmaceutical narcotics."