mischance vs vis major

mischance

noun

  • A mishap, an unlucky circumstance. 

  • Bad luck, misfortune. 

verb

  • To undergo (a misfortune); to suffer (something unfortunate). 

vis major

noun

  • A greater force; "act of God"; unavoidable accident. 

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