indomitability vs indomitableness

indomitability

noun

  • The quality of being indomitable. 

  • The quality of being undefeated, resolute, and tenacious. 

indomitableness

noun

  • Quality of being indomitable. 

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