lock out vs shut out

lock out

verb
  • To inadvertently prevent (a person, particularly oneself) from entering a place, by leaving it locked. 

  • To prevent from accessing a data structure. 

noun
  • An event in which an employer bars employees from working as a tactic in negotiating terms of employment, particularly in response to a strike or threat to strike. 

shut out

verb
  • To prevent from entering; to block or exclude. 

  • To prevent from scoring; to perform a shutout. 

  • To hide from sight. 

  • To refuse to be open and vulnerable toward. 

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