proper right vs starboard

proper right

noun
  • The direction which is to the right from an object's perspective, the direction 90 degrees clockwise from the front. 

starboard

noun
  • The righthand side of a ship, boat or aircraft when facing the front, or fore or bow. Used to unambiguously refer to directions according to the sides of the vessel, rather than those of a crew member or object. 

  • One of the two traditional watches aboard a ship standing a watch in two. 

verb
  • To put to the right, or starboard, side of a vessel. 

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