each individual. You're making an assumption that the percentage will always be covered. And what happens if you get to a point where someone is let go for no reason at all and they just say, "but we have to cut a certain number of people so you're out of luck." Who decides which people?
That's not the answer. The only answer for letting people go is better evaluations and climate surveys. You can't go about it any other way than looking at each individual.