tranquil vs unstirring

tranquil

adj
  • Calm; without motion or sound. 

  • Free from emotional or mental disturbance. 

unstirring

adj
  • Without stirring; quiet and still. 

  • Not stirring or rousing; not inspiring the emotions. 

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