Obviously these are estimates and not precise. Normally when we cost something, we look at the key factors—the key cost drivers, for example—and then we provide sensitivity relative to changes in the assumptions we have made in doing the costing.
For example, if you make an assumption that by providing a pharmacare program there will be a reduction in the price of prescription drugs because there is power to negotiate better, that's unknown. That's an assumption that you have to make. We can change that assumption and see how the result will change relative to the different assumptions, from high to low and through the range.