downfall vs expiration

downfall

noun
  • A precipitous decline in fortune; death or rapid deterioration, as in status or wealth. 

  • The cause of such a fall; a critical blow or error. 

  • An act of falling down. 

verb
  • To fall down; deteriorate; decline. 

expiration

noun
  • A cessation, extinction, ending 

  • That which is produced by breathing out, as a sound. 

  • Emission of volatile matter; exhalation. 

  • The last emission of breath; death. 

  • The act of expiring. 

  • The act or process of breathing out, or forcing air from the lungs through the nose or mouth 

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