math_fact: 1919 is a member of the Fibonacci-type sequence starting with 2 and 7.
trivia: 1919 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: April 2nd is the day in 2004 that Islamist terrorists involved in the 11 March 2004 Madrid attacks attempt to bomb the Spanish high-speed train AVE near Madrid.