run its course vs shut down

run its course

verb
  • To come to a natural end. 

shut down

verb
  • To close, terminate, or end. 

  • To pass (another vehicle), especially quickly. 

  • To turn off or stop. 

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

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