With youth usage and perception of harm having significantly increased the past 4 it would be better to compare data to 10 years ago not last year.
Links
[1] http://www.samhsa.gov/data/sites/default/files/report_2121/ShortReport-2121.html
[2] http://rethinkpot.org/tags/youth
[3] http://rethinkpot.org/tags/samhsa