And if the slope is decreasing over that time, then our estimate would be an overestimate of the actual amount in the landfill. And to figure out whether the slope is increasing or decreasing, we just have to look at the value of the second derivative. If the second derivative is positive, that means our slope is increasing, which means that our extrapolation would be an understatement. Let me just be clear here. Let me draw this. Let me make it very clear. So let me just draw a random function.