It is possible that you are under a false impression here. Factors for this might be the availability of news reports about crashes (e.g. you just didn't get to know about all those crashes in, say, Africa in the 90s) or an increase of air traffic while the flight:crash ratio might be stable I haven't looked up all those numbers but it is a good thing to keep these factors in mind.

A similar issue is the perceived increase of crime, while the actual numbers tell a different story: an astonishing decrease of crime rate since the 90s.