constancy vs interruption

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. 

interruption

noun
  • The act of interrupting, or the state of being interrupted. 

  • A time interval during which there is a cessation of something. 

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