When did Ray Bolger start dancing?

Bolger did start dancing professionally in Vaudeville at age 20. * "Unlike many of the male vaudeville dancers of that era, like James Barton, John Bubbles and Jack Donahue he took dance lessons. He had his first serious dance recital at age 18" but had been taking classes well before that. I am sorry I cannot tell you at what age he started as there doesn't seem to be a record of that. Only that he took dance lessons when he was an adolescent.