cusk vs sunfish

cusk

noun
  • A marine cod-like fish in the ling family Lotidae, Brosme brosme. 

sunfish

noun
  • Any of various large marine fishes of the family Molidae that have an oval compressed body. 

  • Any of various small freshwater fishes of the family Centrarchidae, often with iridescent colours and having a laterally compressed body. 

How often have the words cusk and sunfish occurred in a corpus of books? (source: Google Ngram Viewer )