I don't alter quotes, even for PC reasons. And If I am going to reuse language for effect I am not going to make changes unless they add to the point I am making. The first comment said man-years and I stuck with that as I wasn't trying to correct their gender grammar.

Also, "person-year" is vague as "persons" includes non-humans entities such as corporations and partnerships. "Man-year" refers only to work by biological humans. "People-years" might be better but that is plural. Had I been the first I might have used person-years, but when someone else sets a precedent that avoids confusion I'm happy to stick with it despite potential microaggressions.