During the same period, even more students have driven after drinking alcohol or have ridden with a drunk driver.
These national problem college drinking stats are alarming enough, but what I found even more discouraging was that older college students are drinking and driving more frequently than younger students.
That is the conclusion of a new study that will be published in the August issue of Alcoholism: Clinical & Experimental Research.
Research has typically suggested that freshmen are the most reckless college drinkers, but this might not be true when students get behind the wheel. You'd think that students would grow in maturity as they age, but it looks more likely that they regress when they get near a six pack and a set of car keys.
According to the new study, 25% of 21-year-old college students admitted they had driven drunk in the past month compared with 17% of 19-year-olds and 20% of 20-year-olds. In addition, 63% of 21-year-old students had driven after drinking compared with 19-year-olds (42%) and 20-year-olds (48%).
Why do older students drink and drive more?One of the authors of the study, Robert B. Voas, senior scientist and director of the Impaired Driving Center at the Pacific Institute for Research and Evaluation, offered this suggestion: "This study tends to demonstrate that alcohol-related problem behaviors increase with age, perhaps due to greater opportunities for risk taking such as owning a car or the ability to patronize bars and purchase alcohol."
Based on their findings, the researchers argued that allowing younger Americans to drink legally would not be wise. "Lowering the drinking age to 18 would likely result in a surge of alcohol-related traffic problems given that younger students would have even less driving experience," says Amelia Arria, who is at the University of Maryland's School of Public Health.
The researchers also questioned the effectiveness of attempts by colleges to quell student drinking. Walk on just about any campus on a Friday or Saturday night and I think you'll know how to answer that one.
More on CBSMoneyWatch:Problem College Drinking: 2 Reasons for Hope
Drinking and driving image by pmarkham. CC 2.0.