adapt vs maintain

adapt

verb
  • To make suitable; to make to correspond; to fit or suit 

  • To fit by alteration; to modify or remodel for a different purpose; to adjust 

  • To make by altering or fitting something else; to produce by change of form or character 

  • To make oneself comfortable to a new thing. 

adj
  • Adapted; fit; suited; suitable. 

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 adapt and maintain occurred in a corpus of books? (source: Google Ngram Viewer )