constancy vs disbelief

constancy

noun
  • The quality of being constant; steadiness or faithfulness in action, affections, purpose, etc. 

  • An unchanging quality or characteristic of a person or thing. 

disbelief

noun
  • Astonishment. 

  • Unpreparedness, unwillingness, or inability to believe that something is the case. 

  • The loss or abandonment of a belief; cessation of belief. 

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