luck out vs strike gold

luck out

verb
  • To experience great luck; to be extremely fortunate or lucky. 

  • To be unfortunate or unlucky; to run out of luck. 

strike gold

verb
  • To be lucky, to win or be successful. 

  • To find gold 

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