fragility vs pliability

fragility

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

  • Weakness; feebleness. 

pliability

noun
  • The quality or state of being pliable; flexibility; pliableness. 

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