austerity vs rigidness

austerity

noun
  • Severity of manners or life; extreme rigor or strictness; harsh discipline. 

  • A policy of deficit-cutting, which by definition requires lower spending, higher taxes, or both. 

  • Freedom from adornment; plainness; severe simplicity. 

rigidness

noun
  • Rigidity. 

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