carte blanche vs power of choice

carte blanche

noun
  • Unlimited discretionary power to act; unrestricted authority. 

  • A blank paper that is signed by some authority and given to a person to fill as he or she pleases. 

adv
  • As an undifferentiated mass, without regard to distinctions; willy-nilly. (Possibly from confusion with another French phrase, en masse.) 

power of choice

How often have the words carte blanche and power of choice occurred in a corpus of books? (source: Google Ngram Viewer )