roustabout vs sailor

roustabout

noun
  • an unskilled laborer, especially at an oilfield, at a circus or on a ship, 19th c. 

sailor

noun
  • A person in the business of navigating ships or other vessels 

  • Any of various nymphalid butterflies of the genera Neptis, Pseudoneptis and Phaedyma, having white markings on a dark base and commonly flying by gliding. 

  • A member of the crew of a vessel; a mariner; a common seaman. 

  • A person who sails sailing boats as a sport or recreation. 

  • Someone knowledgeable in the practical management of ships. 

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