Statistics are increasingly proving cannabis use among teenagers dropped in states where cannabis is legal, according to the National Survey on Drug Use and Health (NSDUH).

Colorado reported the most significant drop, where the rates between individuals aged 12-17 fell almost 2 percent from 11.13 percent in 2014 and 2015 to 9.08 percent in 2015 and 2016. The survey also found Colorado teens are consuming less cannabis than they did before legalization.

Washington saw a similar drop in teen use as well. The rates among individuals aged 12-17 fell from 9.17 percent in 2014 and 2015 to 7.93 percent in 2015 and 2016.

Oregon and Washington D.C. reported decreases in teen use as well, whereas Alaska was the only cannabis-legal state to report an increase, where percentages increased from 18.44 in 2014 and 2015 to 18.86 in 2015 2016.

“Colorado is effectively regulating marijuana for adult use,” said Brian Vincente — one of the lead organizers of the ballot measure that legalized social cannabis in Colorado — in a statement. “Teen use appears to be dropping now that state and local authorities are overseeing the production and sale of marijuana. There are serious penalties for selling to minors, and regulated cannabis businesses are being vigilant in checking IDs. The days of arresting thousands of adults in order to prevent teens from using marijuana are over.”

State legalization is increasingly providing researchers the opportunity to compare populations where cannabis is legal with states where it is illegal. Last month, a study reported that opioid overdose deaths in Colorado decreased by 6 percent from 2014 to 2016.

Colorado has also been investigating the effects of cannabis on driving: two local universities obtained over $800,000 in funding to explore the relationships between dabbing and safe driving. Before legalization, it would have been impossible for researchers to obtain the cannabis concentrates to perform the study.