stringency vs unshakability

stringency

noun
  • A rigorous imposition of standards. 

  • A tightness or constriction. 

  • A scarcity of money or credit. 

unshakability

noun
  • The quality or state of being unshakable. 

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