2019 · In 2021, 35.4% of young adults aged 18 to 25 (11.8 million people) reported using marijuana in the past year. 1 According to the Monitoring the Future survey, rates of past year marijuana use among middle and high school students have remained relatively steady since the late 1990s. In 2022, 30.7% of 12th graders reported using marijuana in the.