Legalized recreational marijuana sales are on a roll, reaching nearly $1 billion in 2015, says a new report that predicts sales will continue to grow in 2016.

Recreational sales for adults grew 184 percent to $998 million from just $351 million in 2014, according to the fourth edition of “The State of Legal Marijuana Markets.” That is a joint report from ArcView Market Research and New Frontier, a cannabis analytics firm.

The sale of marijuana for recreational use is legal in Colorado, Washington, Oregon, Alaska and the District of Columbia.

The report estimates that total legal cannabis sales nationally — including medical marijuana programs in 23 states and Washington, D.C. — grew to $5.4 billion from $4.6 billion in 2014.

The report says demand will remain strong in 2016, pushing legal markets to grow to $6.7 billion, a nearly 25 percent increase over 2015. By 2020, legal market sales have the potential to reach $21.8 billion, with adult use sales making up about two-thirds of sales.

“By almost every metric the legalization and regulation of adult use” has been a success in Colorado, where recreational sales began in January 2014, and Washington state, which began recreational sales in July 2014, the report says:

Crime is down, falling prices have made the legal market increasingly competitive against the black market, regulatory compliance is high as businesses dare not risk losing their valuable licenses, and product quality and diversity has increased.

However, Keith Humphreys, a professor of psychiatry and behavioral sciences at the Stanford University School of Medicine and marijuana policy researcher, was less enthusiastic. He told the International Business Times:

“If one of our long-legal drugs, alcohol or tobacco, had this kind of dizzying rise in sales, would there be a breathless, braggy press release about it? Americans have internalized culturally that explosive growth in adult tobacco and/or alcohol sales is a cause for concern, but not that explosive growth in cannabis sales is too.”

Voters in California, Nevada, Arizona, Massachusetts, Maine, Rhode Island and Vermont will decide on legalization of recreational use this year, and Florida, Ohio, Missouri and Pennsylvania will vote on medical marijuana legalization, says MarketWatch.

Nearly 6 in 10 Americans favor the legalization of marijuana, according to a recent Gallup poll.

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