extramural vs independent

extramural

adj
  • Taking place outside the walls of an institution, especially a school or university. 

  • Describing teaching of students who are not resident at such an institution. 

independent

adj
  • Providing a comfortable livelihood. 

  • Not dependent; not contingent or depending on something else; free. 

  • Not affiliated with any political party. 

  • Separate from; exclusive; irrespective. 

  • Not subject to bias or influence; self-directing. 

noun
  • A team not affiliated with any league or conference. 

  • A neutral or uncommitted person. 

  • A candidate or voter not affiliated with any political party, a freethinker, free of a party platform. 

  • A small, privately owned business. 

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