Valve has announced that a total of 28,981,249,043 zombies have been bludgeoned, hacked apart, perforated or exploded since Left 4 Dead 2 was released on 17 November 2009. That's nearly 29 billion in 86 days. Not bad.

The games developer offers a few statistics to compare that number to. The entire population of the planet has been killed 4.26 times over, for starters. It also means that we're about quarter of the way through killing the total number of humans who have ever lived - about 100 billion. If you say a zombie's average height is 6 feet, then you could stack them end to end around the world 1322 times.

We love that Valve implemented a total zombie kill counter in the game in the first place, and hope that the company has a big screen in its HQ that constantly ticks upward at a rate of about 4000 per second. Valve doesn't specify what the total is when you add the figures from the original Left 4 Dead - who knows what heights we've scaled there.

Still, it's a mightily impressive figure. If you've contributed, then give yourself a pat on the back.