Labourers work on an upgrading project of a railway line in Jinyun county, Zhejiang province, August 27, 2013. China's economy grew 7.7 percent in 2012 from the previous year, the National Bureau of Statistics said on Monday, revising its earlier estimate of 7.8 percent published in January. Picture taken August 27, 2013. REUTERS/Lang Lang (CHINA - Tags: BUSINESS CONSTRUCTION TRANSPORT)