Isn't it 1%? If the oldest of the 380 has been operating for a year and they were produced at an even rate, their average age should be six months.

I don't know much about car accidents, but 1%/year sounds like a lot. Can one even legally sell a car model if 1% of the cars are going to crash lethally in the first year? Or evne 0.5, or 0.2%?