mausoleum vs potter's field

mausoleum

noun
  • A large stately tomb or a building housing such a tomb or several tombs. 

  • A gloomy, usually large room or building. 

potter's field

noun
  • A public place where strangers, paupers, and criminals are buried. 

How often have the words mausoleum and potter's field occurred in a corpus of books? (source: Google Ngram Viewer )