From NRA-ILA:

Overall, the study notes, between 2007 and 2014, as permit numbers have increased, “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.”