groundbreaker vs torchbearer

groundbreaker

noun
  • First person to do, make or fight for something. A pioneer; a seminal person. 

torchbearer

noun
  • The leader of a campaign, or one who gives inspiration to others. 

  • A person who carries a torch (flaming brand). 

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