Table 1.

Characteristics of the 10669 respondents, China

Characteristics		No.	%
Gender	Male	4864	45.6
	Female	5805	54.4
Age group (y)	18~	1446	13.5
	25~	5898	55.3
	50~	2173	20.4
	65~	1152	10.8
Occupation	Student	729	6.8
	Teacher	429	4.0
	Health care worker	338	3.2
	Office staff	2681	25.1
	Worker	1069	10.0
	Farmer	1212	11.4
	Public service personnel	848	8.0
	Others	3363	31.5
Educational background	Primary school and illiterate	1202	11.3
	Middle school	4943	46.3
	College and above	4524	42.4