Four line charts about the percent of high school seniors who think people are at great risk of harming themselves by using marijuana, cocaine, LSD, and heroin, 1987-07.

For marijuana, the percent began at 73.5 in 1987 and increased to 78.6 in 1991. Then the percent fell to a low of 53.0 in 2002. Then it fluctuates with a high of 58.0 as it increases to 54.8 in 2007. The percent then dropped to 51.7 in 2008.

For cocaine, the percent began at 88.5 in 1987 and increased to 91.1 in 1990. After 1990, the percent decreased to 82.2 in 2004. Then it fluctuates with a high of 84.6 as it increases to 83.3 in 2007. In 2008, the percent fell to 80.7.

For LSD, the percent began at 83.8 in 1987 and increased to 84.5 in 1990. After 1990, the percent decreased to 67.3 in 2007. Then the percent dropped to a low of 63.6 in 2008.

For heroin, the percent began at 88.7 in 1987 and increased to 90.2 in 1990. Then the percent dropped to a low of 86.8 in 2004. After 2004, it fluctuates with a high of 89.7 as it increases to 87.8 in 2007. Then the percent decreased to 86.4 in 2008.