But how to combine them, i.e., micromorts per skydiving jump via a car that travels 250 miles in the air before driving it out of the back of a cargo plane? I

But how to combine them, i.e., micromorts per skydiving jump via a car that travels 250 miles in the air before driving it out of the back of a cargo plane? I think we should just add them together and call it 9 micromorts, assuming the car has an appropriately sized parachute.