mark down vs necropsy

mark down

verb
  • To write down. 

  • To write a memorandum about. 

  • To reduce the price of. 

  • To subtract marks or points from, for an error. 

  • To draw a conclusion about something; to consider something to be a certain way. (Typically used with as.) 

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 mark down and necropsy occurred in a corpus of books? (source: Google Ngram Viewer )