author vs librarian

author

noun
  • Someone who writes books for a living. 

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

verb
  • To create a work as its author. 

librarian

noun
  • One who cares for the publications, files etc. in a library, whether staff or volunteer. 

  • The keeper, manager of a library. 

  • A person who processes and organizes information. 

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