How do you get meaningful stats when the product definition keeps mutating?
50 years ago all
SF and
Fantasy were shelved together in many book stores (many are still tagged that way today)
Today there are many (sub)categories that were once lumped together
Back then there was a small Comic book rack (Superman for 10 - 25 cents) at Woolworths.
Today there are stores that are devoted to Graphic Novels (prices not even close to 10 cents
)
GN's and Audio books are now in the mix of the SF fix
I don't believe SF is really dying