Some additional information

Where do the numbers come from?

A variety of sources, including:

• The National Safety Council
• The Center for Disease Control
• Emerging Infectious Diseases at the CDC
• This Live Science article, which references additional sources.

How accurate are they?

It varies. Some risks have pretty clear answers. For instance, you can count the number of people who die in motor vehicle accidents each year. Some risks are largely based on certain assumptions: the odds of dying in a terrorist attack in the US depends on how often you think they will occur (we assumed a single "9/11" level event in your lifetime). Others risks are in the middle: for asteroids we can calculate the statistical chance of an impact for a given size, and estimate the number of deaths that would occur.

But I don't drive a car, so it's different for me, right?

No, these aren't individual, personal risks, they're averaged over the whole population. Think of it from society's perspective: if you were President, which risks would you want to pay the most attention?

Credits: Spider image courtesy Wikimedia Commons.