shut down vs shut off

shut down

verb
  • To turn off or stop. 

  • To pass (another vehicle), especially quickly. 

  • To close, terminate, or end. 

  • To emotionally withdraw into oneself as a defense mechanism; to block out external stressors. 

shut off

verb
  • To stop or turn off. 

  • To separate; to isolate. 

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