feebleness vs firmness

feebleness

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

firmness

noun
  • security; steadfastness; good grip 

  • strictness; mental strength 

  • physical durability; rigidness (of material) 

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