constancy vs inquietude

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. 

inquietude

noun
  • A condition of being restless, uneasy or nervous. 

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