The use of cocaine and amphetamines among high school seniors in the U.S. continues to decrease, according to recently released data from the 2008 Monitoring the Future survey.

The percentage of 12th graders reporting past year use of cocaine has decreased slightly in recent years (from 5.7% in 2006 to 4.4% in 2008) and amphetamine use decreased from the most recent high of 11.1% in 2002 to 6.8% in 2008. In addition, the use of methamphetamine — a type of amphetamine — has decreased as well, reaching a low of 1.2% in 2008.

Lloyd Johnston, the study’s principal investigator, notes that “the use of this highly addictive drug is now down by about two thirds among teens since 1999, when its use was first measured.”