serenity vs stolidness

serenity

noun
  • The state of being serene; calmness; peacefulness. 

  • A lack of agitation or disturbance. 

  • A title given to a reigning prince or similar dignitary. 

stolidness

noun
  • The quality of being stolid. 

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