bankroller vs croupier

bankroller

noun
  • One who bankrolls; usually an individual who has enough seed capital to launch a venture; one who can fund a project; angel investor. 

croupier

noun
  • The person who collects bets and pays out winnings at a gambling table, such as in a casino. 

  • One who, at a public dinner party, sits at the lower end of the table as assistant chairman. 

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