Literary reputations
Somewhat on the way down:
Overall, in other searches also, I see a golden age for "high fiction" in the 1950-1970 period.
Holding steady:
Dwindling:
Up, but down since 2000
On the way up:
Other than very recent authors, these are harder to find than you might think.
Falling off a cliff:
Typing in "Arnold Bennett" is like shooting fish in a barrel.