Since 1987, the Bulletin of the Atomic Scientists has been counting up each country's nuclear arsenal in its Nuclear Notebook, peeling back the veil of secrecy that often surrounds these numbers. The Bulletin has now gone and made its Nuclear Notebook into a neat interactive graphic.
There are nine nuclear states: the US, Russia, the United Kingdom, France, China, India, Pakistan, Israel and North Korea. The 70 years worth of data isn't necessarily surprising, but it really drives home how the world's nuclear arsenal is completely dominated by the U.S. and Russia. The other countries barely register as a blip.
The full interactive graphic lets you sift through the data country by country and year by year. Check it out at the Bulletin's website.