expel vs maintain

expel

verb
  • To eject or erupt. 

  • To remove from membership. 

  • To deport. 

maintain

verb
  • To keep up; to preserve; to uphold (a state, condition etc.). 

  • To declare or affirm (a clause) to be true; to assert. 

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