boneyard vs memorial park

boneyard

noun
  • A graveyard. 

  • A dumpsite for obsolete or unusable aircraft. 

  • In the game of dominoes, the pile of upside-down pieces that have yet to be used. 

memorial park

noun
  • A cemetery. 

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