Firearm background checks for gun permits rose 6.4 percent in May compared with a year earlier, marking the first year-to-year increase since January, according to the Federal Bureau of Investigation.

The number of background checks initiated through the National Instant Criminal Background Check system reached 1,580,980 in May, compared with 1,485,259 in May 2014 and 1,711,340 in April, 2015.

Background checks, which are considered a leading indicator of gun sales, jumped 19 percent in 2012 and another 7.7 percent in 2013 before falling slightly in 2014.