WASHINGTON (CBS DC) — A surge in the number of Americans with permits to carry concealed weapons coincides with a significant drop in violent crime in the U.S., a new report finds.

The “Concealed Carry Permit Holders Across the United States” report from the Crime Prevention Research Center released Wednesday analyzed parallels between a 22 percent drop in the overall violent crime rate in the same time period in which the percentage of the adult population with concealed carry permits soared by 130 percent.

The report finds that 11.1 million Americans now have permits to carry concealed weapons, which are up from 4.5 million in 2007. This 146 percent increase parallels a nearly one-quarter (22 percent) drop in both murder and violent crime rates during the same time period.

Regarding right-to-carry laws as a form of deterrence to violent crime, the study authors note that the large majority of peer-reviewed academic studies conclude that permitted concealed handguns reduce violent crime. Those debates center around those who claim concealed handgun permits reduce crime and those who say it has no effect. The CPRC report focuses on states that allow right-to-carry permits and states that don’t require permits for concealed weapons rather than just the amount of permits.

Additionally, the report notes that the number of concealed carry permit holders “is likely much higher than 11.1 million,” because numbers are not available for all statues that issue permits, such as New York. And four states and the vast majority of Montana don’t require residents to have a permit to carry concealed handguns within the state – most of those permits are issued to carry outside the state.

Using that foundation, the report finds that the six states that allow people to carry concealed handguns without a permit have much lower murder and violent crime rates than the six states with the lowest permit rates. Additionally, the murder rate is nearly one-quarter (23 percent) lower in states not requiring permits, and the violent crime rate is 12 percent lower.

The murder and violent crime rates are lower in the 25 states with the highest permit rates compared to the rest of the U.S.

“When you allow people to carry concealed handguns, you see changes in the behavior of criminals,” John R. Lott, the center’s president, told Fox News. “Some criminals stop committing crimes, others move on to crimes in which they don’t come into contact with victims and others actually move to areas where they have less fear of being confronted by armed victims.”

Although cautioning that nationwide “simple cross-sectional comparisons” can present misleading data, the report used new state -level permit data from 2007 on to determine that for each one percentage point increase in the percent of the U.S. adult population holding permits is roughly paralleled with a 1.4 percent drop in the murder rate.

“We found that the size of the drop [in crime] is directly related to the percentage of the population with permits,” Lott told Fox News.

A few highlights of the concealed carry data by state: Florida has issued the most concealed carry permits at 1.28 million, although South Dakota, Indiana and Alabama all sit above 10 percent for the state’s population that holds concealed carry permits. Eight percent or more of the population in 10 states hold concealed carry permits.

The number of permits increased by roughly 2.7 million permit holders in 1999 to 4.6 million eight years later in 2007. But in December 2011, the federal Government Accountability Office estimated that there were at least 8 million concealed handgun permits, and by June 2014 that number had increased beyond 11.1 million U.S. adults.

The CPRC notes on its website that much of the academic research on gun data is supported by foundations and funding that are more interested in researching gun violence and gun control legislation rather than purely scientific analysis of guns, crime and public safety. In addition to founding the CPRC, Dr. John R. Lott, Jr. is an economist, crime expert and author of books including “More Guns, Less Crime,” “The Bias Against Guns,” and “Freedomnomics.”