bonanza vs windfall

bonanza

noun
  • Anything which is a great source of wealth or yields a large income or return. 

  • The point at which two mother lodes intersect. 

  • A rich mine or vein of silver or gold. 

windfall

noun
  • A sudden large benefit; especially, a sudden or unexpected large amount of money, as from lottery or sweepstakes winnings or an unexpected inheritance or gift. 

  • Something that has been blown down by the wind. 

  • A fruit that has fallen from a tree naturally, as from wind. 

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