mortality vs transience

mortality

noun
  • Death. 

  • The number of deaths per given unit of population over a given period of time. 

  • Deaths resulting from an event (such as a war, epidemic or disaster). 

  • The state of being susceptible to death. 

transience

noun
  • An impermanence that suggests the inevitability of ending or dying. 

  • The quality of being transient, temporary, brief or fleeting. 

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