FROM JOHN LOTT, ET AL.: Concealed Carry Permit Holders Across the United States. Some high points:

Since President Obama’s election the number of concealed handgun permits has soared, growing from 4.6 million in 2007 to over 12.8 million this year. Among the findings in our report:
— The number of concealed handgun permits is increasing at an ever- increasing rate. Over the past year, 1.7 million additional new permits have been issued – a 15.4% increase in just one single year. This is the largest ever single-year increase in the number of concealed handgun permits.
— 5.2% of the total adult population has a permit.
— Five states now have more than 10% of their adult population with concealed handgun permits.
— In ten states, a permit is no longer required to carry in all or virtually all of the state. This is a major reason why legal carrying handguns is growing so much faster than the number of permits.
— Since 2007, permits for women has increased by 270% and for men by 156%.
— Some evidence suggests that permit holding by minorities is increasing more than twice as fast as for whites.
— Between 2007 and 2014, murder rates have fallen from 5.6 to 4.2 (preliminary estimates) per 100,000. This represents a 25% drop in the murder rate at the same time that the percentage of the adult population with permits soared by 156%. Overall violent crime also fell by 25 percent over that period of time.
— States with the largest increase in permits have seen the largest relative drops in murder rates.
— Concealed handgun permit holders are extremely law-abiding. In Florida and Texas, permit holders are convicted of misdemeanors or felonies at one-sixth the rate that police officers are convicted.

More at the link.