millionaire vs squillionaire

millionaire

noun
  • A person whose net worth is at or greater than one million units of the local currency; a multimillionaire. 

  • A person whose net worth is at or greater than one million units of the local currency, but less than two million. 

squillionaire

noun
  • An incredibly rich person. 

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