box office vs onlookers

box office

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

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

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

onlookers

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