adjure vs invoke

adjure

verb
  • To earnestly appeal to or advise; to charge solemnly. 

  • To issue a formal command. 

invoke

verb
  • To solicit, petition for, appeal to a favorable attitude. 

  • To appeal for validation to a (notably cited) authority. 

  • To cause (a program or subroutine) to execute. 

  • To conjure up with incantations. 

  • To call to mind (something) for some purpose. 

  • To bring about as an inevitable consequence. 

  • To call upon (a person, a god) for help, assistance or guidance. 

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