author vs litterateur

author

noun
  • The originator or creator of a work, especially of a literary composition. 

  • Someone who writes books for a living. 

verb
  • To create a work as its author. 

litterateur

noun
  • A person engaged in various literary works: literary critic, essayist, writer. 

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