Since Colorado made recreational marijuana use legal for adults age 21 and up, the rates at which they’re using cannabis have increased. At the same time, the percentage of youth who use marijuana has not.

The information comes from two recent surveys by the Colorado Department of Public Health and Environment. One of the surveys, the Behavioral Risk Factor Surveillance System, determined that adult marijuana use increased from 13.6 percent in 2016 to 15.5 percent in 2017 with 18- to 34-year-olds being the biggest driving force behind that spike.

Much of this meshes with state and local sales tax reports, which have shown a rapidly expanding industry in terms of sales since 2014.

Meanwhile, the 2017 Healthy Kids Colorado Survey, done biennially, shows that one in five children currently uses marijuana. That suggests that marijuana use among youth has not changed since legalization because 20 percent of children reported they used marijuana in 2013.

Fast-forward to 2017, and 19 percent of children said they had. The national average for youth marijuana use also remains at 20 percent.

According to researchers, the survey also found that children’s attitudes about marijuana haven’t changed much since Colorado moved to make recreational use legal for adults.

Both the 2015 and 2017 Healthy Kids Colorado Surveys found about half of kids thought of marijuana as risky, felt it was easy to get underage and said it was wrong for youth to use underage.

Surprisingly, though, children also think that up to four out of five of their peers — a whopping 80 percent — use marijuana, even though only one in five actually claim to.

Though the number of adults using marijuana has increased, the surveys show the number of those driving high has not. According to the survey, only 3 percent of adults reported driving while high in 2016 and 2017.

According to the report, research shows underage marijuana use can impair developing brains and hamper young people’s efforts to achieve their goals. Also, children who have trusted adults in their lives are less likely to use marijuana.

“Preventing young people from using marijuana is a statewide priority,” said Gov. John Hickenlooper in a statement. “While youth use hasn’t gone up, we are working hard to educate Colorado parents and their children about the health and legal risks of underage marijuana use.”