Recent changes in Chinese government policies that have permitted companies to operate as capitalistic ventures merely let the genie out of the bottle. With their population and determination the only surprising thing to me is that it took this long for them to become the number two economy in the world.
Taking a simple-minded look at the rate of growth in the animation, one wonders if they are headed for Number One. In the time-frame used, the American GDP grows by roughly 35 times while the Chinese is about 244 times larger than it began.