harbinger vs necropsy

harbinger

verb
  • To announce or precede; to be a harbinger of. 

noun
  • A person or thing that foreshadows or foretells the coming of someone or something. 

necropsy

verb
  • The act of performing a necropsy. 

noun
  • The pathological examination of a corpse, particularly to determine cause of death. 

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