comforter vs preserver

comforter

noun
  • A person who comforts someone who is suffering. 

  • A pacifier. 

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

preserver

noun
  • A life preserver. 

  • A person who prepares preserves of fruit or preserved meats. 

  • A person who refinishes furniture. 

  • One who preserves. 

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