shush vs shut down

shush

verb
  • To be quiet; to keep quiet. 

  • To ask someone to be quiet, especially by saying shh. 

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. 

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