coliseum vs seventh art

coliseum

noun
  • A large theatre, cinema, or stadium. 

  • A large, often circular building, for indoor sporting events, exhibitions, concerts, etc.; arena. 

seventh art

noun
  • Chiefly preceded by the: the art of making motion pictures; filmmaking. 

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