| 序号 | 时间 (年) |
数据 (公里/平方公里) |
|---|---|---|
| 1 | 2023 | |
| 2 | 2022 | |
| 3 | 2021 | |
| 4 | 2020 | |
| 5 | 2019 | |
| 6 | 2018 | |
| 7 | 2017 | 8.52 |
| 8 | 2016 | 8.30 |
| 9 | 2015 | 8.26 |
| 10 | 2014 | 7.43 |
| 11 | 2013 | 8.19 |
| 12 | 2012 | 7.80 |
| 13 | 2011 | 7.38 |
| 14 | 2010 | 6.95 |
| 15 | 2009 | 7.39 |
| 16 | 2008 | 7.22 |
| 17 | 2007 | 6.44 |
| 18 | 2006 | 6.00 |
