deadliness vs mortality

deadliness

noun
  • The quality of being deadly. 

  • The degree to which a thing is deadly. 

  • Tedium, or the quality of being boring. 

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. 

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