Pollyanna vs wet blanket

Pollyanna

noun
  • One who is persistently cheerful and optimistic, even when given cause not to be so. 

  • A secret Santa gift exchange. 

name
  • A female given name from Hebrew derived from Polly and Anna; rare in the real world. 

wet blanket

noun
  • A person who takes the fun out of a situation or activity, as by pessimism, demands, dullness, etc. 

  • A timid person; one who lacks confidence; a wimp. 

  • Used other than figuratively or idiomatically: see wet, blanket. 

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