downer vs optimist

downer

noun
  • A livestock animal that has collapsed. 

  • A negative drug trip. 

  • A form of industrial action in which workers down tools and refuse to work. 

  • Something or someone disagreeable, dispiriting or depressing; a killjoy. 

  • A drug that has depressant qualities. 

optimist

noun
  • a person who expects a favourable outcome 

  • a believer in optimism 

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