With the high economic growth in Japan before the 90s Japanese wages increased a lot. This gave opportunities to countries like China which at the time had an enormous potential cheap labor force to manufacture goods for exporting to the Western world. With the high economic growth in China wages are rising. Mexico seems the next country to benefit from low wages.
A likely reason why Canada is still a relatively big player is it's favorable location.
Due to a request by the Economist this graph has been removed.