crematorium vs necropolis

crematorium

noun
  • A place where the bodies of dead people are cremated. 

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 crematorium and necropolis occurred in a corpus of books? (source: Google Ngram Viewer )