boards vs box office

boards

noun
  • A stage (as in a theater). 

  • A hardcover binding on a book. 

  • Examinations given for entry to college or to qualify for a profession. 

  • Structure around a rink for ice hockey. 

box office

noun
  • A place where tickets are sold in a theatre/theater or cinema. 

  • The total amount of money paid by people worldwide to watch a movie at cinemas/movie theaters. 

  • Quality of an entertainment or spectacle that makes it very popular with the public, or likely to be so. 

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