callousness vs monstrousness

callousness

noun
  • The quality of being callous; emotional hardheartedness or indifference. 

  • The quality of having calluses. 

monstrousness

noun
  • The state or condition of being monstrous. 

  • Something monstrous. 

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