fragility vs longevity

fragility

noun
  • Weakness; feebleness. 

  • The condition or quality of being fragile; brittleness; frangibility. 

longevity

noun
  • Duration over time; persistence. 

  • The quality of being long-lasting, especially of life. 

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