backstory vs forelife

backstory

noun
  • The previous life and experiences of a person, especially a character in a dramatic work, but also a real-life person. 

  • A fictitious account of a person's history designed to conceal their actual history and motives. 

  • A prequel. 

forelife

noun
  • A former or previous life 

  • Early or primitive life; protozoa 

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