levity vs sense of humour

levity

noun
  • Lightness of manner or speech, frivolity; lack of appropriate seriousness; inclination to make a joke of serious matters. 

  • A lighthearted or frivolous act. 

  • The state or quality of being light, buoyancy. 

sense of humour

noun
  • The quality of an individual to find certain things funny. 

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