I wonder if they just added up all the kids who've ever performed on Broadway (Annie, Miss Saigon, Les Miz, the King and I, Oliver, Billy Elliot, etc...) and the number of people under 18 in that same time frame and did the math from there. It sounds like it could be figured out so many ways...and with many different outcomes!
"This thread reads like a series of White House memos." — Mister Matt