Sociodemographic characteristics of the subjects by survey year
| Survey year | ||||||||
|---|---|---|---|---|---|---|---|---|
| Characteristic | 1991 | 1993 | 1997 | 2000 | 2004 | 2006 | 2009 | 2011 |
| No of subjects | 1319 | 1400 | 1654 | 1937 | 2140 | 2331 | 2613 | 2880 |
| Age group (years), % | ||||||||
| 60–70 | 64.7 | 64.6 | 62.5 | 61.6 | 58.1 | 57.4 | 57.1 | 57.0 |
| 70–80 | 28.9 | 28.8 | 29.5 | 30.2 | 33.4 | 33.7 | 32.9 | 32.3 |
| 80+ | 6.4 | 6.6 | 8.0 | 8.2 | 8.5 | 8.9 | 10.0 | 10.7 |
| Gender, % | ||||||||
| Male | 48.2 | 47.4 | 46.1 | 46.1 | 47.4 | 47.0 | 47.5 | 46.9 |
| Female | 51.8 | 52.6 | 53.9 | 53.9 | 52.6 | 53.0 | 52.5 | 53.1 |
| Income, RMB/person×year* | ||||||||
| Low | 1094.8 | 1128.6 | 1199.6 | 1248.3 | 1708.3 | 1782.2 | 2928.8 | 3014.8 |
| Medium | 2594.5 | 2619.2 | 2902.6 | 4016.6 | 5131.1 | 5226.2 | 8608.9 | 10209.3 |
| High | 4634.7 | 5524.1 | 5870.9 | 8699.1 | 12346.5 | 13892.6 | 19713.8 | 23976.2 |
| Urbanicity index, score† | ||||||||
| Low | 30.3 | 30.7 | 33.6 | 40.9 | 41.4 | 41.7 | 47.2 | 49.8 |
| Medium | 52.8 | 54.8 | 61.6 | 67.5 | 70.5 | 70.7 | 72.8 | 76.0 |
| High | 66.1 | 68.7 | 76.0 | 80.5 | 86.8 | 89.3 | 90.6 | 92.6 |
*Per capita annual household income (RMB/person×year), inflated to 2011. Values presented as median of each tertile.
†Measured at the community level on a 12-component continuous scale ranging from 0 to 120. Values presented as median of each tertile.