WSJ reports:

It’s typically advisable not to accept Chinese economic data at face value –as even the country’s own premier will tell you. Figures on everything from inflation and industrial output to energy consumption and international trade often don’t seem to gel with observation and sometimes struggle to stack up when compared with other indicators.

Read more: http://blogs.wsj.com/chinarealtime/2013/06/19/a-rare-look-into-how-china-fudges-its-numbers/