In 2010 the proportion of eighth-graders who reported using an illicit drug in the past 12 months jumped to 16%, up from 14.5% in 2009. Past-year use of an illicit drug was 30% for tenth-graders and 38% for 12th-graders in 2010. The increases were fueled by higher rates of marijuana use, according to the 2010 Monitoring the Future Survey (MTF). In 2010 daily use of marijuana was reported by 6.1% of high school seniors, 3.3% of tenth-graders, and 1.2% of eighth-graders, compared with 2009 rates of 5.2%, 2.8%, and 1.0%, respectively. The MTF is an annual series of classroom surveys of eighth-, tenth-, and 12th-graders conducted by researchers at the University of Michigan, Ann Arbor, under a grant from the National Institute on Drug Abuse (NIDA).