| 序号 | 时间 (年) |
数据 (公里/万平方公里) |
|---|---|---|
| 1 | 2021 | |
| 2 | 2020 | |
| 3 | 2019 | |
| 4 | 2018 | |
| 5 | 2017 | |
| 6 | 2016 | |
| 7 | 2015 | |
| 8 | 2014 | |
| 9 | 2013 | |
| 10 | 2012 | |
| 11 | 2011 | 26.91 |
| 12 | 2010 | 26.39 |
| 13 | 2009 | 23.05 |
| 14 | 2008 | 17.57 |
| 15 | 2007 | 17.57 |
| 16 | 2006 | 17.57 |
| 17 | 2005 | 16.97 |
| 18 | 2004 | 18.01 |
| 19 | 2003 | 18.07 |
| 20 | 2002 | 18.08 |
| 21 | 2001 | 18.08 |
| 22 | 2000 | 18.08 |
| 23 | 1995 | 12.24 |
| 24 | 1990 | 9.48 |
| 25 | 1985 | 9.48 |
| 26 | 1978 | 6.19 |
