| 序号 | 时间 (年) |
数据 (公里/平方公里) |
|---|---|---|
| 1 | 2022 | |
| 2 | 2021 | |
| 3 | 2020 | |
| 4 | 2019 | |
| 5 | 2018 | |
| 6 | 2017 | |
| 7 | 2016 | 8.49 |
| 8 | 2015 | 8.71 |
| 9 | 2014 | 7.92 |
| 10 | 2013 | 7.59 |
| 11 | 2012 | 7.35 |
| 12 | 2011 | 6.94 |
| 13 | 2010 | 6.08 |
| 14 | 2009 | 5.82 |
| 15 | 2008 | 5.40 |
| 16 | 2007 | 5.31 |
| 17 | 2006 | 4.14 |
