quiet as a mouse vs unruffled

quiet as a mouse

adj
  • Very quiet, so as to not be heard 

unruffled

adj
  • Calm, not ruffled, serene, at peace, unbothered. 

  • Not ruffled or tousled. 

How often have the words quiet as a mouse and unruffled occurred in a corpus of books? (source: Google Ngram Viewer )