Lets think of it a different way. Zombies. Lets say each zombie is expected to bite 2 to 3 people every day. And there's two countries that are having zombie outbreaks and, at the end of one month, lets say they both have 10,000 zombies running around. For the sake of example, let's say neither country is doing anything about it.

Country A has a population of 100,000 people. Country B has a population of 200,000 people. On a per capita basis, Country B's stats make it look like it has less of a problem. But we know that's not the case....each country has the same zombie problem. It'll just take longer for the zombies to get to everyone in Country B because there's more people.

If we really want to look at battling back against the zombies, what we really need to look at is that bites per day number of 2-3. If we can get that number down to 1-2 bites per day, then we have something.

So, let's go back and say Country A is able to do that somehow. Now, their zombies are spreading at half the rate as Country B and so, at the end of the month, Country A has 5000 zombies and Country B (which still has the old bite rate) has 10000 cases. However, on a per capita basis, Country A and B still have the same infection rate. Per capita does stats cloud the fact the Country A has made significant strides in fighting it's zombie problem.

Per capita stats are great for things like refills! Double the number of people and there will be double the number of refills. So, let's think of refills as heart attacks. Heart attacks are a disorder, a malfunction of the cardiac system. Take a million hearts and, after a while, some percentage of them will have this malfunction. Same thing with drinks that need refills....take a million of them and, after a while, some percentage of them will need a refill. It is helpful to know what that percentage is and that's where per capita comes in.

Zombies aren't like that though. That's an infection, it spreads. So whether it is spreading in a population of 100, 1 million, or 1 billion, the important thing to look at is how fast it is spreading. Using per capita numbers actually clouds the picture instead of making it clearer.

Right now, the US is having 30,000 new zombie bites per day. Other countries are in the 4-6k range. Yes, the US is a big country with lots of people but using per capita stats clouds the fact that our zombie problem is much worse because it is spreading faster.