general_fact: 913 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 913 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 913 is an uninteresting number.
historical_date: July 1st is the day in 1915 that Lieutenant Kurt Wintgens achieves the first known aerial victory with a synchronized gun-equipped fighter plane, the Fokker M.5K/MG Eindecker.