general_fact: 9311 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 9311 is the index of a prime Fibonacci number.
trivia: 9311 is an uninteresting number.
historical_date: June 28th is the day in 1948 that Boxer Dick Turpin beats Vince Hawkins at Villa Park in Birmingham to become the first black British boxing champion in the modern era.