Conversation so far:
What was Vaslav Nijinsky biography?
Vaslav Nijinsky was born in 1889 or 1890 in Kiev, Russian Empire, as Wacław Niżyński, to ethnic Polish parents
Who were Vaslav Nijinsky parents?
touring dancers Tomasz Niżyński and Eleonora Bereda
How did Vaslav Nijinsky get interested in ballet?
Vaslav Nijinsky was introduced to dance by his parents
How long did Vaslav Nijinsky perform with his parents?

Question: How long did he stay in Kiev?
Self-contained rewrite: How long did Vaslav Nijinsky stay in Kiev?