A worker at a cannabis greenhouse at the growing facility of the Tikun Olam company on March 7, 2011 near the northern city of Safed, Israel. In conjunction with Israel's Health Ministry, Tikon Olam are currently distributing cannabis for medicinal purposes to over 1800 people in Israel. Uriel Sinai/Getty Marijuana could be the next mega-industry in the US.

A new report from New Frontier Data, a business intelligence firm focused on cannabis, projects the legal weed market will create more than a quarter of a million jobs by 2020. In comparison, manufacturing jobs are expected to decline by 814,000 by 2024, according to the Bureau of Labor Statistics.

2016 was a watershed year for the budding industry. Eight states voted to legalize pot in some form, bringing the number of states with comprehensive medical marijuana laws to 28. One in five Americans can legally get high without a letter from a doctor.

As more people leave the black market for the safety, convenience, and product diversity that legal dispensaries offer, the industry's job growth could explode.

Legal marijuana businesses employed an estimated 100,000 to 150,000 workers in January, according to the Marijuana Business Daily. That estimate includes growers, scientists, dispensary employees, and tech entrepreneurs developing ancillary services like the "Yelp of weed" or "Uber for pot."

New Frontier based its projections on an analysis from the Marijuana Policy Group, an economic and policy cannabis consulting firm that works with the state of Colorado. The report assumes every state will have a medical and adult-use market in place by 2020 — a rather optimistic outlook. It's also banking on the belief that President Donald Trump will stand by his vow to support states' rights to legislate their own marijuana policy, despite warnings of a crackdown from Press Secretary Sean Spicer and Attorney General Jeff Sessions.

Giadha Aguirre De Carcer, founder and CEO of New Frontier Data, described the forecast as "an optimal view of the market that demonstrates what potential job creation could be if legal cannabis is operating freely and openly," in a statement.

Dispensary employees, called "budtenders," man the counter at medical marijuana shop Caliva in San Jose, California. Caliva

There's some evidence to suggest New Frontier's projections are on the right track. In Colorado, which legalized pot outright in 2012 and opened the recreational market in 2014, the industry has created roughly 18,000 jobs, according to the Marijuana Policy Group.

California, home to the world's sixth largest economy, fully legalized marijuana last November. Its state capital region alone could see 20,000 jobs created if it becomes a hub for the industry.

The legal marijuana market is expected to top $24.5 billion in 2025, based solely on the states that passed medical or recreational legalization initiatives before 2017.