Table 1.

Characteristics.

Characteristics	Participants (N = 9952)
Age, No. (%)
16–35 yr	3329 (33.5)
36–55 yr	3327 (33.4)
56–75 yr	3296 (33.1)
Gender, No. (%)
Female	4887 (49.1)
Male	5056 (50.9)
Education level, No. (%)
Primary school or below	2641 (26.5)
Junior high school	4011 (40.3)
High school	2180 (21.9)
University or above	1120 (11.3)
Annual household income, No. (%)
<¥10000	818 (8.2)
¥10,000–¥29,999	5085 (51.1)
¥30,000–¥49,999	2470 (24.8)
≥¥50,000	1579 (15.9)
Location, No. (%)
Rural	4883 (49.1)
Urban	5069 (50.9)