| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.756 | 52 |
| 2015 | 3.513 | 63 |
| 2014 | 4.307 | 56 |
| 2013 | 4.24 | 60 |
| 2012 | 3.916 | 73 |
| 2011 | 4.025 | 75 |
| 2010 | 1.213 | 142 |
| 2009 | 1.456 | 143 |
| 2008 | 3.078 | 131 |
| 2007 | 5.003 | 84 |
| 2006 | 6.72 | 52 |
| 2005 | 1.662 | 150 |
| 2004 | 5.108 | 59 |
| 2003 | 15.831 | 13 |
| 2002 | 22.861 | 9 |
| 2001 | 16.224 | 12 |
| 2000 | 15.721 | 21 |
| 1999 | 19.749 | 22 |
| 1998 | 16.214 | 30 |
| 1997 | 12.999 | 43 |
| 1996 | 17.155 | 33 |
| 1995 | 21.155 | 28 |
| 1994 | 23.118 | 24 |
| 1993 | 22.099 | 24 |
| 1992 | 20.148 | 23 |
| 1991 | 22.529 | 24 |
| 1990 | 22.917 | 21 |