America's two largest publicly traded gun manufacturers announced massive earnings boosts this week, thanks, as you might expect, to America's massive boost in gun buying.

Smith & Wesson reported quarterly earnings triple what it saw a year ago, on sales totaling over $136 million. Sturm, Ruger & Co. had a similarly blockbuster quarter, with sales of $141.8 million. And this is only two publicly traded companies; as The Times reported in January, sales of AR-15 rifles, made by the privately held Bushmaster, were clearing shelves.

Shortly after the massacre in Newtown, each company's stock price plummeted. In the intervening months, each has nearly recovered its losses — and it's easy to see why. Ruger and Smith & Wesson's quarterly net sales have increased substantially since 2010. (Note: The companies' financial quarters don't overlap entirely.)

Unsurprisingly, those increases correlate closely to the number of background checks completed by the FBI, numbers that the agency regularly makes public. The background checks, it's worth noting, are for all gun sales at stores, not just those from the two companies represented.

Year over year, those background checks have increased dramatically. The blue line below is the average number of monthly background checks between 1999 and 2010. Each year since, monthly checks have increased. The past three months have seen the most monthly background checks since record-keeping began.

But this isn't the entire picture. As we noted yesterday, background checks only cover an estimated 60 percent of gun sales. Sales at gun shows and between private citizens don't currently require one. If that figure is accurate, it means that the total number of gun sales last year topped 30 million — one gun sale for every ten Americans.

It also means that the government would be taking on an additional 13 million background checks annually if checks for private sales and gun shows are mandated by law. Nowhere will need more support if that were to happen than Kentucky, which so far this year has seen far more background checks than any other state — even independent of its smaller population.

One last map, for those curious. This is the percent change in background checks by state between October and November 2012 — in other words, before and after the reelection of President Obama.

Of course, executives at Smith & Wesson and Ruger see that map differently than you do. Instead of blue, they see green.