cop out vs go west

cop out

verb
  • To plead guilty and ask for mercy. 

  • To avoid or shirk, either by failing to perform, or by performing in a grossly insufficient, negligent, or superficial manner. 

go west

verb
  • Synonym of set: to move toward the western horizon, to go down. 

  • Used other than figuratively or idiomatically: see go, west. 

  • To move to the American West, particularly (historical) during the 19th century era. 

How often have the words cop out and go west occurred in a corpus of books? (source: Google Ngram Viewer )