| 序号 | 时间 (年) |
数据 (万平方公里) |
|---|---|---|
| 1 | 2019 | |
| 2 | 2018 | |
| 3 | 2017 | |
| 4 | 2016 | |
| 5 | 2015 | |
| 6 | 2014 | |
| 7 | 2013 | 0.16 |
| 8 | 2012 | 0.16 |
| 9 | 2011 | 0.16 |
| 10 | 2010 | 0.16 |
| 11 | 2009 | 0.16 |
| 12 | 2008 | 0.16 |
| 13 | 2007 | 0.16 |
| 14 | 2006 | 0.16 |
| 15 | 2005 | 0.16 |
| 16 | 2004 | 0.16 |
| 17 | 2003 | 0.16 |
| 18 | 2002 | 0.16 |
| 19 | 2001 | 0.16 |
| 20 | 2000 | 0.16 |
| 21 | 1999 | 0.16 |
| 22 | 1998 | 0.16 |
| 23 | 1997 | 0.16 |
| 24 | 1996 | 0.16 |
| 25 | 1995 | 0.16 |
| 26 | 1994 | 0.16 |
| 27 | 1993 | 0.16 |
| 28 | 1992 | 0.16 |
| 29 | 1991 | 0.16 |
| 30 | 1990 | 0.16 |
