Teens’ rates of vaping nicotine and marijuana leveled off this year, but rates remain high, according to the most recent figures from the annual Monitoring the Future survey.

From 2017 to 2019, the percentage of teens who said they vaped nicotine in the past year roughly doubled for eighth graders from 7.5% to 16.5%, for 10th graders from 15.8% to 30.7%, and for 12th graders from 18.8% to 35.3%. Rates held steady in early 2020, the survey found.

The survey also found marijuana vaping rates leveled off after a twofold increase over the past two years, HealthDay reports. In 2020, 8.1% of eighth graders, 19.1% of 10th graders and 22.1% of 12th graders said they vaped marijuana.

“The rapid rise of teen nicotine vaping in recent years has been unprecedented and deeply concerning since we know that nicotine is highly addictive and can be delivered at high doses by vaping devices, which may also contain other toxic chemicals that may be harmful when inhaled,” National Institute on Drug Abuse Director Nora Volkow said in a news release. “It is encouraging to see a leveling off of this trend, though the rates still remain very high.”