impetrate vs require

impetrate

verb
  • To ask for; to demand. 

  • To obtain by asking; to procure upon request. 

require

verb
  • To demand, to insist upon (having); to call for authoritatively. 

  • To demand of (someone) to do something. 

  • Naturally to demand (something) as indispensable; to need, to call for as necessary. 

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