centerfold vs cover girl

centerfold

noun
  • Any very sexually attractive person, who is therefore material for such a photograph. 

  • A large photograph printed on this sheet, typically in the form of a nude, or provocatively dressed, sexually attractive woman or man. 

  • The person appearing in such a photograph. 

  • The single sheet of paper that forms the middle two pages of a magazine or other publication. 

cover girl

noun
  • An attractive, usually well-known, female model whose image has been featured on one or more magazine covers. 

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