SOS vs presage

SOS

noun
  • A children's game in which players take turns to place S's and O's on a grid, collecting points by creating an "SOS" sequence. 

  • The conventional Morse code call made by a ship in distress. 

presage

noun
  • A warning of a future event; an omen. 

  • An intuition of a future event; a presentiment. 

verb
  • To make a prediction. 

  • To have a presentiment of; to feel beforehand; to foreknow. 

  • To predict or foretell something. 

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