armed robbery vs stickup

armed robbery

noun
  • An theft where the thieves are carrying weapons. 

stickup

noun
  • A robbery at gunpoint. 

  • A small-diameter tree branch or limb that extends out of the water in flooded or submerged timber, as in a lake or river. 

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