feebleness vs infirmity

feebleness

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

infirmity

noun
  • a moral weakness or defect 

  • feebleness, frailty or ailment, especially due to old age. 

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