blue movie vs porn

blue movie

noun
  • a pornographic film 

porn

noun
  • A pornographic work. 

  • Material, usually visual, presenting something desirable in a sensational manner. 

  • Material that provides illicit gratification of an obsessive or unhealthy interest in something. 

  • Pornography. 

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