The number of American high school students vaping nicotine rose dramatically between 2017 and 2018, according to new survey results published by the University of Michigan's Institute for Social Research. The percentage of 12th grade students who reported vaping nicotine within the previous 30 days rose from 11 percent in 2017 to 21 percent last year; that translates into an increase of 1.3 million nicotine vapers over the course of the year. The use of many other drugs remained steady, according to the survey, while the percentage of students using prescription opioids and tranquilizers declined, as did the percentage of students binge drinking.