restrain vs simmer down

restrain

verb
  • To control or keep in check. 

  • To deprive of liberty. 

  • To strain again. 

  • To restrict or limit. 

simmer down

verb
  • To decrease in intensity of anger, agitation, or excitement. 

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