paper trail vs whyfor

paper trail

noun
  • A written record, history, or collection of evidence. 

  • Records left by a person or organization in the course of activities. 

  • Physical evidence of something that occurred in the past. 

whyfor

adv
  • why; for what reason 

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