Story highlights

About 7.3% of Americans age 12 or older used marijuana regularly in 2012, survey finds

Marijuana is legal in two states, while 20 more allow medical use

Heroin use is up 70% since 2007, according to the survey

CNN  — 

As laws across the country become less restrictive, more Americans are reporting using marijuana regularly than ever before, according to a new survey by the Substance Abuse and Mental Health Services Administration.

The National Survey on Drug Use and Health – the largest of its kind – is done annually. Results from the past five years have shown a steady increase in weed use. Last year was no exception.

In 2012, about 7.3% of Americans ages 12 or older reported regularly using marijuana. That’s up from 7% of Americans in 2011. Although it’s only a slight increase, the real contrast exists between 2012 and 2007, when 5.8% of Americans said they regularly used weed.

These numbers could represent an increase in use among Americans, or simply an increase in the number of people who felt OK reporting use of the drug on a national survey.

There has been a lot of attention given to marijuana in the last few years. U.S. Attorney General Eric Holder announced last week that the federal government would no longer prosecute people who used the drug in states where it was legal – as long as there were state laws in place to keep the drug away from children.

Until that announcement, people could be brought up on federal charges even if they were within the law in their state.

How to regulate pot when it’s legal

Washington and Colorado have both legalized recreational marijuana use. Some 20 other states allow people to purchase it for medical reasons.

The survey, which looks at all drug and alcohol use, showed some other interesting trends as well.

Prescription drug abuse, which has been increasing in the past few years, has leveled off. But heroin use is on the rise; the number of people using heroin is up some 80% since 2007.

Nearly 24 million Americans – that’s 9.2% of the population – say they use illicit drugs, according to the survey.

Are American opinions on weed reaching the tipping point?