airiness vs nonchalance

airiness

noun
  • The quality of being airy. 

  • The quality of being light in quality or manner. 

  • insubstantiality 

nonchalance

noun
  • Indifference, unconcern; carelessness; coolness; disregard, detachment. 

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