affability vs insouciance

affability

noun
  • The state or quality of being affable, friendly, or approachable. 

insouciance

noun
  • Carelessness, heedlessness, indifference, or casual unconcern. 

  • Nonchalance. 

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