power off vs pull the plug

power off

verb
  • To turn off, to cut the power to. 

pull the plug

verb
  • to unplug or cut power 

  • to cease to support; to halt 

  • to cease or turn off life support 

  • to cease production or publication. 

How often have the words power off and pull the plug occurred in a corpus of books? (source: Google Ngram Viewer )