This dovetails with the previous answer. We actually spend a lot of time going through economic modelling on these issues. You also have to factor in the yield of that customer. When we crunch through the model, it really looks as though the best way to deploy our investment is with about 45% in the U.S., about 27% in Asia Pacific, about one quarter in Western Europe, and then that last 4% or 5% in Brazil and Mexico.
We monitor that on an annual basis, knowing two things. First of all, you can't pull in and out of markets too quickly, because sustained marketing takes some time to get traction. There's a different visitor mix in some of those markets, so that some of them are more visiting friends and family, some of them are more doing business travel, some of them are more doing independent leisure travel. That figures its way into the mix as well.
We also look at air access as an important piece of that. I'll use both China and India as an example. We've had fairly limited air access to those markets over the last few years, so even though the growth numbers, from a percentage basis, look pretty dramatic, the numbers themselves are not that dramatic because of the limits on the amount of air access available to us. We see in both those markets a tremendous increase in air access over the last 12 months, and probably going forward in the next 14 to 18 months, so that factors into our decisions there as well.