About 29% of the world population is under 18. About 37% of the world population is adult females so that would follow, all other things being equal. But they rarely are.
In almost any disaster, with rare exceptions, adult males tend die in the highest numbers. The few exceptions tend to be cases where schools were hit however even in those cases the number of adult males killed tended to be substantial as they are usually the rescue workers and many of them perish.
As the pirate with the peg leg said, I stand corrected.