According to a federal data survey released this week, rates of cannabis consumption among American teenagers 12 to 17 dropped to their lowest rate in two decades.

Last year, 5.6 percent of adolescents consumed cannabis on a monthly basis, which represented a statistically significant drop from 7.2 percent when social cannabis was first legalized in Washington state and Colorado in 2014.

The statistical trend defies the opposition of cannabis legalization which claims legal cannabis would encourage youth to consume more.

The last time adolescent cannabis use was this low was 1994, according to the survey.