A just-released national survey indicates that 47% of Chinese cannot communicate in standard spoken Putonghua, state media reported. The survey sample involved 470,000 people across China, a fact that testifies to the validity of the study, state media said. China officially claims to have 56 ethnic groups and seven main Chinese dialects, each subdividing into dialectic variations. This always leads to a pitiful loss of efficiency, reports said. Only in 2001 did China formally promulgate legislation requiring Putonghua to be used in education, broadcasting and the public service, although campaigns encouraging its use go back a decade and more.