| 序号 | 时间 (年) |
数据 (人/户) |
|---|---|---|
| 1 | 2019 | |
| 2 | 2018 | |
| 3 | 2017 | |
| 4 | 2016 | |
| 5 | 2015 | |
| 6 | 2014 | |
| 7 | 2013 | 3.60 |
| 8 | 2012 | 3.60 |
| 9 | 2011 | 3.60 |
| 10 | 2010 | 3.50 |
| 11 | 2005 | 3.80 |
| 12 | 2000 | 4.00 |
| 13 | 1995 | 4.00 |
| 14 | 1990 | 4.00 |
| 15 | 1985 | 4.50 |
| 16 | 1980 | 4.80 |
| 17 | 1978 | 4.70 |
