insouciance vs passivity

insouciance

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

  • Nonchalance. 

passivity

noun
  • The state of being passive. 

  • A lack of initiative. 

  • Submissiveness. 

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