Christmas card vs sympathy card

Christmas card

noun
  • A greeting card that is decorated in a manner that celebrates Christmas. 

sympathy card

noun
  • A greeting card sent to family members of one who has died to express regret. 

  • An attempt to score points in a discussion by portraying oneself as a victim in need of sympathy (used with the verb "play"). 

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