groundbreaker vs procreator

groundbreaker

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

procreator

noun
  • One who originates or creates something. 

  • One who procreates; a father or mother. 

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