highway robbery vs padding

highway robbery

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

  • Said of excessive or exorbitant prices. 

padding

noun
  • Extra characters such as spaces added to a record to fill it out to a fixed length. 

  • Soft filling material used in cushions etc. 

  • Extraneous text added to a message for the purpose of concealing its beginning, ending, or length. 

  • Anything of little value used to fill up space. 

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