chantage vs daylight robbery

chantage

noun
  • blackmail; the extortion of money by threats of scandalous revelations 

daylight robbery

noun
  • The practice of cheating or of imposing an exorbitant charge for a product or service; (countable, rare) an instance of this. 

  • Conduct which unfairly deprives an opponent of an advantage or a win; (countable, rare) an instance of this. 

  • Used other than figuratively or idiomatically: see daylight, robbery. 

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