armed robbery vs hold-up

armed robbery

noun
  • An theft where the thieves are carrying weapons. 

hold-up

noun
  • A robbery at gunpoint. 

  • Women's stockings designed to be worn without suspenders. 

  • A delay or wait. 

  • The holding back of a card that could win a trick in order to use it later. 

  • The inventory of nuclear material within a separation plant. 

How often have the words armed robbery and hold-up occurred in a corpus of books? (source: Google Ngram Viewer )