adjure vs impetrate

adjure

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

  • To issue a formal command. 

impetrate

verb
  • To ask for; to demand. 

  • To obtain by asking; to procure upon request. 

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