[simion314]

Maybe you want to state it more clearly, like in math so I can have a better idea what you are talking about. I think I missunderstood you anyway, because I was thinking at airplane crashes statistics and not at the entire world industry.

In statistics you need some basic things to be true, like you need true random independent events, or sometimes a theorem apply only if the distribution of the events is known to have some properties.

What I understood you were implying (I was wrong, sorry) and other comments too, is that if we look at Boeing crashes (not MAX) for latest N years (but we exclude older incidents) then we can conclude things about the future statistics of the MAX.

About the rest of the industry I agree that most things got better. But for example in car industry there was a lot of competition and a lot of regulation bout safety and pollution that forced the companies to be better, if you had only 2 car making companies and have them self approve then we may get in the same situation as with the MAX.