copilot vs windjammer

copilot

noun
  • A backup or assistant pilot of an aircraft. 

verb
  • To serve as relief or assistant pilot. 

windjammer

noun
  • A member of the crew of a ship of this kind. 

  • A sailing ship; especially a large, iron-hulled, square-rigged ship with three or more masts. 

  • A windbag, a loquacious person. 

  • A weatherproof jacket (windcheater). 

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