There's lots of debates in the Space world about the safety margins of modern rockets (specifically the fact that the ITS isn't planned to have an abort mode as (in the words of many SpaceX supporters), it "should be as safe as airplanes").
Now, I know that modern airplanes are crazy safe (as in, the last fatal crash of a major US airline in the US was just a month after 9/11), but I presume that back in the 1920s seats on airplanes were sold commercially without passengers having an abort mode either, and those airplanes were much less reliable than modern ones.
How has the accident per flight statistics changed throughout aviation history?