millionaire vs multimillionaire

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. 

multimillionaire

noun
  • A person whose net worth is multiple million dollars, pounds, euros or some other currency. 

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