Wikipedia entity: British military bands
Topics: statistics; music; age; gender
Original sentence: The average age of the 304 drummers at Waterloo was 25, with about 10% being boys under 16.
Quantified sentence: The average age of the 304 drummers at Waterloo was 25, with some being boys under 16.
Quantifier: some
Percentage: 10%
Specificity: unable