It seems silly to be worried about this sort of thing given to low likelihood of a crash in the first place. Most measures of flight risk are in "flight hours",

It seems silly to be worried about this sort of thing given to low likelihood of a crash in the first place. Most measures of flight risk are in "flight hours", so it's hard to make a direct single-flight measure. But most of the sources I was able to find quickly ranged from about 1/1MM to 1/10MM, largely depending on the airlines and countries out of which they are operating. I'll use 1/5MM for my purposes (if anyone has a better idea, pipe in). So, if one were to look at the survival rates in the chart as "per flight" versus "per crash", it would be. First Class: 49% * (1/5MM) = .0000098% Ahead of Wing: 56% * (1/5MM) = .0000112% Over Wing: 56% * (1/5MM) = .0000112% Rear: 69% * (1/5MM) = .0000138% [edit: cleaned up for readability]