Pilgrim vs dark horse

Pilgrim

noun
  • A settler of the Plymouth Colony. 

  • Someone connected with Plymouth Argyle Football Club, as a fan, player, coach etc. 

name
  • A surname. 

dark horse

noun
  • A candidate for an election who is nominated unexpectedly, without previously having been discussed or considered as a likely choice. 

  • Someone who possesses talents or favorable characteristics that are not known or expected by others. 

  • Used other than figuratively or idiomatically: see dark, horse. 

  • A horse whose capabilities are not known. 

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