The demand for pilots is derived from the demand for air travel as this article makes clear. Boeing says Asia needs 240,000 pilots over next two decade including nearly a quarter of a million in China alone! There are, of course, also price elasticity of supply issues to consider, given the cost and duration of training to fly commercial planes. To put this in a little context, Wikipedia claims that there were 290,000 commercial airline pilots in the world in 2017.