adjure vs encourage

adjure

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

  • To issue a formal command. 

encourage

verb
  • To spur on, strongly recommend. 

  • To mentally support; to motivate, give courage, hope or spirit. 

  • To foster, give help or patronage 

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