 So what we do in a Monte Carlo simulation is we take the asset mix that you're using, let's say 60% stocks, 40% bonds, and we look at the historical average for returns and volatility. We call that standard deviation. How far does the asset move from its average? And then we run 1,000 different trials to get to the same average. And we figure, okay, if you made it out of 90% of those, then you're in good shape.