Before a gun can be used to hunt, for protection, or in a mass shooting like Wednesday’s tragic killing in San Bernardino, California that left 14 victims dead and 17 wounded, it must be bought. That one sale is a single dot in a multibillion-dollar industry, one that is coming under new scrutiny during the post-massacre gun control debate. Here's a by the numbers breakdown.

$13.5 billion

Annual revenue of gun and ammunition manufacturing industry, with a $1.5 billion profit. (IBIS World)

$3.1 billion

Annual revenue of gun and ammunition stores, with a $478.4 million profit. (IBIS World)

10,847,792

The number of pistols, revolvers, rifles, shotguns and miscellaneous firearms manufactured in the U.S. in 2013, the latest full year available. That's 4,441,726 pistols, 725,282 revolvers, 3,979,570 rifles, 1,203,072 shotguns, and 495,142 miscellaneous firearms. (ATF)

4%

Percentage of the above guns which were exported. Of those 10.84 million guns, 10,413,880 stay in America. (ATF)

270-310 million

Estimated number of guns in the U.S. (Pew Research Center)

263,223

Number of full-time jobs related to the firearm industry, up from 209,750 in 2012. (NSSF)

$42.9 billion

Estimated overall economic impact of the firearms and ammo industry in the U.S. (NSSF)

20,968,273

Number of firearm background checks initiated in 2014. Because a background check is required before a gun is bought, this numbers gives insight into gun sale trends. However, just because a background check was initiated doesn't mean a gun was purchased. (FBI)

9,138,123

Number of firearm background checks in 1999. (FBI)

5

Average number of firearms owned by a gun owner once you toss out the top 3% of gun owners who own more than 25 guns. (Journal of Injury Prevention)

31%

Percentage of American households with guns. (NORC)

29%, 43.7%, 55.9%

Adults living in a household with firearms: percentage by suburbs, other urban areas, and rural counties, respectively. (NORC)

60%

Percentage of Americans who say personal safety/protection is the reason they own a gun. (Gallup)

$229 billion

The cost of fatal and non-fatal gun violence to the U.S. in 2012, representing 1.4% of total gross domestic product.(Mother Jones)