constancy vs peculiarity

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. 

peculiarity

noun
  • Exclusive possession or right. 

  • That which is peculiar; a special and distinctive characteristic or habit; particularity. 

  • The quality or state of being peculiar; individuality; singularity. 

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