Actually, it's not that hard to do. The question is who's ideas of the various components will be assumed to be correct. We have to use a statistics approach to such things as power and metal prices. Predicting the future has to be tempered. Everyone here knows what I think the next couple of years will be like. That's not too hard to predict. It's the 5-10 years out that becomes vague. Still, the reality is that you can use say Highland for example and see that a refurb equals a hell of a lot more profit than the DCF method. Not having to put down new infastructure is a huge savings. Prices went up since those guidlines were done so when they went to build that one they estimated wrong. There are plenty of examples from the past.