The number of law-abiding citizens carrying concealed firearms for self-defense outside the home is on the rise while, at the same time, crime rates are on the decline, according to a new report published on Wednesday by the Crime Prevention Research Center.

By the numbers, the report states:

Three states (South Dakota, Indiana, and Alabama) now have over 10 percent of their adult populations with permits, and 10 states have at least 8 percent of their adult populations with permits.

The number of concealed carry permit holders is likely much higher than 11.1 million.

Between 2007 and the preliminary estimates for 2013, murder rates have fallen from 5.6 to 4.4 per 100,000 – a 22 percent drop in the murder rate at the same time that the percentage of the adult population with permits soared by 130 percent. Overall violent crime also fell by 22 percent over that period of time.

John Lott, founder and president of CPRC, discussed the overall findings with Fox News.

“When you allow people to carry concealed handguns, you see changes in the behavior of criminals,” said Lott, who is also a Fox News contributor. “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.”

For Lott there’s a causal relationship between the number of concealed carry permit holders and crime rates. In a sense, more guns creates less crime. To that end, Lott claims that one percentage point increase in the number of CCW holders yields a 1.4 percent drop in the murder rate for that area.

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

However, there are many who believe that suggesting there is a causal relationship between the two metrics is a bit of a stretch considering all the various inputs that effect crime rates.

“I think we have to be cautious about having a causal relationship between gun permits and a decrease in crime,” said Tod Burke, a professor of criminal justice at Radford University, in Radford, Virginia. “[Lott’s] theory is one to consider, but not to the exclusion of others.”

Burke believes there are other factors that influence crime rates and may explain the reduction, such as “data-driven” policing and the increased incarceration of violent criminals.