| 时间 | 值 | 世界排名 |
|---|---|---|
| 2016 | 0 | 139 |
| 2015 | 0.9 | 116 |
| 2014 | 0.9 | 121 |
| 2013 | 0.1 | 136 |
| 2012 | 2.3 | 106 |
| 2011 | 4.9 | 98 |
| 2010 | 4.1 | 99 |
| 2009 | 0.6 | 122 |
| 2008 | 1 | 120 |
| 2007 | 1 | 120 |
| 2006 | 1.1 | 120 |
| 2005 | 1.3 | 116 |
| 2004 | 1.3 | 120 |
| 2003 | 1.5 | 122 |
| 2002 | 1.2 | 123 |
| 2001 | 1.5 | 133 |
| 2000 | 1.4 | 134 |
| 1999 | 1.4 | 135 |
| 1998 | 1 | 134 |
| 1997 | 1 | 134 |
| 1996 | 0.7 | 139 |
| 1995 | 0.4 | 139 |
| 1994 | 0.4 | 140 |
| 1993 | 0.3 | 142 |
| 1992 | 0.2 | 136 |