pan out vs strike gold

pan out

verb
  • To separate and recover (valuable minerals) by swirling dirt or crushed rock in a pan of water, in the manner of a traditional prospector seeking gold. 

  • To proceed according to plan; to result or end up. 

strike gold

verb
  • To find gold 

  • To be lucky, to win or be successful. 

How often have the words pan out and strike gold occurred in a corpus of books? (source: Google Ngram Viewer )