By the time young people reach the 10th grade, only three in ten are non-drinkers. Results of a study indicate that about a third of high school students are moderate to heavy drinkers in the classification of the scientists who organized students into six categories: abstainers, infrequent, light, moderate, moderate-to-heavy and heavy drinkers. Ease of availability is related to heavier drinking. Those states that allow 18-year-olds to purchase alcohol have heavier drinking.
National Institute on Alcohol Abuse, in Homemade, August, 1985