Kungfu Panda,
The airline that has 20 ASRs per 1000 departures might have a much more pro-active safety culture that strongly encourages incident and risk reporting thus allowing the airline to have a better awareness of where the risks are and allows it to mitigate those risks more effectively than 12 per 1000 departure airline where the risks are not being identified as successfully. Which airline is more at risk?
My point is that numbers on their own are pretty ineffective in communicating how safe an airline is. Experience is important but no more so than company culture, training, rostering/fatigue etc etc etc. As a group of professionals we probably shouldn't encourage passengers to reduce complex issues into overly simplistic equations such as experience=safe, it isn't in anyone's interest.