States with stricter gun laws and lower rates of gun ownership in general saw a lower rate of mass shootings between 1998 and 2015 than did other jurisdictions where gun laws were more relaxed, according to a new study.

A study published in The BMJ found a significantly higher rate of mass shootings and other gun crimes in states that had higher rates of gun ownership among the population.

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"States with more permissive gun laws and greater gun ownership had higher rates of mass shootings, and a growing divide appears to be emerging between restrictive and permissive states," the study concluded.

"A 10% increase in state gun ownership [in a state] was associated with a significant 35.1% higher rate of mass shootings," the study said.

The study's co-author told Newsweek in an interview that researchers were surprised to see such a clear divide between states with less- and more-restrictive gun laws.

“It’s hard to be 100 percent certain that what we found isn't possibly because states that experience more mass shootings in turn change their gun laws, or some other factors that we just couldn’t measure," Paul Reeping told Newsweek.

"However, we did include multiple state-level factors that we could measure — education, poverty, incarceration rate, etc. — and took into account a time lag to limit the reverse effect of mass shootings influencing state gun laws across a 15 year period," he added.

“We were surprised most by the growing divergence in recent years of the rates of mass shootings in permissive and restrictive states," Reeper said.

Florida, which last year was the site of the deadly mass shooting at Marjory Stoneman Douglas High School in Parkland, was not included in the study due to imprecise gun ownership stats, according to the study's authors.

Reeping told Newsweek that underreported gun crime statistics likely added to the disparity between less- and more-restrictive jurisdictions.

“Nevertheless, we believe that this underreporting would likely lead to an underestimate of the association that we found, as states with more permissive gun laws appear to be less consistent in their reporting of homicides than states with restrictive gun laws,” he said.