countenance vs imperturbability

countenance

noun
  • Calm facial expression, composure, self-control. 

  • Appearance, especially the features and expression of the face. 

  • Favour; support; encouragement. 

verb
  • To tolerate, support, sanction, patronise or approve of something. 

imperturbability

noun
  • A state of calm, unruffled self-assurance; aplomb, composure. 

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