brittleness vs frailty

brittleness

noun
  • The state of being brittle; aptness to break; fragility. 

  • The property by virtue of which a material is fractured without appreciable deformation by the application of load. 

frailty

noun
  • A fault proceeding from weakness; foible; sin of infirmity. 

  • The condition quality of being frail, physically, mentally, or morally; weakness of resolution; liability to be deceived. 

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