elegance vs self-possession

elegance

noun
  • Restraint and grace of style. 

  • Grace, refinement, and beauty in movement, appearance, or manners. 

  • The beauty of an idea characterized by minimalism and intuitiveness while preserving exactness and precision. 

self-possession

noun
  • calmness and composure, especially when under stress 

  • confidence in one's own powers 

How often have the words elegance and self-possession occurred in a corpus of books? (source: Google Ngram Viewer )