bullpen vs stockyard

bullpen

noun
  • An enclosed area used to hold bulls. 

  • The relief pitchers of a team collectively. 

  • A place for someone or something to get ready. 

  • An enclosed area for pitchers to warm up in during a game. 

  • An open seating arrangement where project teams can communicate openly with minimal effort. 

stockyard

noun
  • An enclosed yard, with pens, sheds etc. or stables, where livestock is kept temporarily before being slaughtered, treated, sold, or shipped etc. 

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