Yes, I understand that, but what I'm getting at is that the reason DND has used 20 years, in my experience, is because.... I mean, even that is an estimate. Someone called it the wag—to a certain extent, the closer you get, the smarter you get.
But I would suggest that it's not hiding anything or anything else. It's just a matter of there's no confidence at all beyond 20 years, and there's a limited amount of confidence even up to 20 years, because of all the unknowables—the cost of fuel, the missions the airplane will do. When we bought the F-18, we didn't know we'd be in Kosovo, Kuwait, or Libya, for example. There are so many unknowables. So I'm suggesting.... I'm not arguing with you on the technical number and so on, but is it a very useful number?