feebleness vs frailty

feebleness

noun
  • The quality or state of being feeble; debility; infirmity. 

frailty

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

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

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