The number of U.S. teens who drink and drive has decreased 54 percent since 1991, according to a new government report. Last year, 90 percent of high school students 16 and older said they don’t drink and drive.

The report, by the Centers for Disease Control and Prevention (CDC), found motor vehicle crashes remain the leading cause of death among American teenagers. “We are moving in the right direction. Rates of teen drinking and driving have been cut in half in 20 years,” CDC Director Thomas R. Frieden, M.D., M.P.H, said in a news release. “But we must keep up the momentum — one in 10 high school teens, aged 16 and older, drinks and drives each month, endangering themselves and others.”

The CDC estimates that almost a million high school teens 16 and older drove after drinking alcohol in 2011. The report states that 85 percent of teens who admitted to drinking and driving also participated in binge drinking in the past month. According to Frieden, younger drivers are 17 times more likely to die in an accident when alcohol is involved.

According to CNN, 10.3 percent of teenagers admitted to drinking and driving last year, compared with 22.3 percent in 1991.

The study found male students were more likely than female students to drink and drive (11.7 percent vs. 8.8 percent). The study found 11.5 percent of Hispanic students, 10.6 percent of white students, and 6.6 percent of African American students said they drink and drive.

The reduction in drinking and driving is due to several factors, including raising the minimum drinking age to 21 across the country, the report notes. Other factors include zero tolerance laws, which do not allow teens to have any alcohol in their system when they drive, and an increase in programs that ease new drivers into full driving privileges, known as graduated driver’s licensing.