Based upon what data? The Golden Age of highjackings was 1968 to 1979. They implemented regulations then to largely stop it. If you head over to the Security forum, you'll hear all of the tin foil hat wearing folks complain about them.

Highjackings are extremely uncommon assurances. I would suggest that you stay out of countries like Belgium with minorities that are prone to extreme violence, fundamentalist religious states and places with political instability or high rates of violent crime in general. That said, the airline part of that doesn't create much of an issue for you.