comforter vs rogation

comforter

noun
  • A person who comforts someone who is suffering. 

  • A pacifier. 

  • A padded cover for a bed, duvet, continental quilt. 

rogation

noun
  • A deeply serious and somber prayer or entreaty. 

  • The demand, by the consuls or tribunes, of a law to be passed by the people; a proposed law or decree. 

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