Marijuana use in Colorado has been much higher than expected, according to a new study by the state.
While only about nine percent of state residents use the drug, they are likely to use 121.4 metric tons of marijuana annually, The Washington Times reports.
The Department of Revenue's Marijuana Enforcement Division, along with the state's Marijuana Policy Group, found the estimates are 31 percent higher than a recent state assessment.
The new study found about 21.8 percent of people using marijuana do so almost daily, and account for almost 70 percent of total marijuana demand. Nationwide, about 17 percent of adults use marijuana almost daily.
The new marijuana use estimates are 89 percent higher than a study by the Colorado Future Center, and 111 percent higher than a study by the Colorado Center for Law and Policy, the article notes.
About 44 percent of all retail sales of marijuana come from tourists, the study found. Tourists are expected to consume about 8.9 metric tons of marijuana annually.
The study found the retail supply of marijuana is growing, while medical marijuana is relatively constant. The authors concluded retail marijuana demand "is derived primarily from out-of-state visitors and from consumers who previously purchased from the Colorado black and gray markets."
In 2012, Colorado and Washington were the first two states to approve measures that allow recreational cultivation and use of marijuana among adults 21 of years or older within each state.