chantry vs predella

chantry

noun
  • A chapel set up for this purpose 

  • An endowment for the maintenance of a priest to sing a daily mass for the souls of specified people 

predella

noun
  • A raised step near the base of a Christian altar. 

  • A carving or painting on this step. 

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