highway robbery vs out of sight

highway robbery

noun
  • The act of robbing a traveler on a public road. 

  • Said of excessive or exorbitant prices. 

out of sight

adj
  • Not yet attainable. 

  • Not accessible to view. 

  • Drunk. 

  • Very expensive. 

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