More Americans are using marijuana, according to a new government report. About 8.4% of Americans ages 12 and older were current users of marijuana last year, up from 7.5% in 2013. The percentage of teens ages 12 to 17 who smoke, drink or use prescription narcotics non-medically has fallen. The percentage of teens who were current marijuana users in 2014 (7.4%) was similar to recent years. Marijuana use grew among adults 26 and older – from 5.6% in 2013 to 6.6% in 2014. Overall, the use of illicit drugs – including marijuana – among Americans aged 12 and older increased from 9.4% in 2013 to 10.2% in 2014. This was especially driven by the increase in adult marijuana use. “The data released today show some signs of progress,” Michael Botticelli, Director of National Drug Control Policy, said in a SAMHSA news release. “However, we still have significant challenges to address.”