Fait mathématique: 9220 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Culture générale: 9220 is a boring number.
Date historique: March 29th is the day in 1999 that the Dow Jones Industrial Average closes above the 10,000 mark (10,006.78) for the first time, during the height of the internet boom.