ashram vs sacellum

ashram

noun
  • A secluded religious hermitage inhabited by gurus, or the population of such a hermitage. 

sacellum

noun
  • In Ancient Rome, a shrine open to the sky, sometimes used for sacrificial purposes, or in honor of the divine. 

  • A small chapel, as a monument within a church. 

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