morgue vs necropolis

morgue

noun
  • A building or room where dead bodies are kept before their proper burial or cremation, (now) particularly in legal and law enforcement contexts. 

necropolis

noun
  • An ancient site used for burying the dead, particularly if consisting of elaborate grave monuments. 

  • A cemetery; especially a large one in or near a city. 

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