… at the University of Michigan, Ann Arbor, under a grant from the National Institute on Drug (NIDA), part of the … of 10th-graders, and 21.6 percent of 12th-graders, down from the 2006 rates of 8.7 percent, 19.9 percent and 25.4 … teen blog, Sara Bellum, Twitter, Facebook, YouTube, or email. Overall, 46,773 students from 400 public and private …