The percentage of U.S. high school students who drink and drive has dropped by more than half in two decades, in part due to tougher laws against driving under the influence of alcohol, health officials said on Tuesday. In 2011, 10.3 per cent of high school students 16 and older reported drinking and driving in the previous 30 days, compared to 22.3 percent in 1991, according to a new Centers for Disease Control and Prevention study.
