| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.64 | 64 |
| 2015 | 2.82 | 92 |
| 2014 | 3.46 | 80 |
| 2013 | 3.27 | 92 |
| 2012 | 3.84 | 78 |
| 2011 | 5.32 | 64 |
| 2010 | 1.83 | 130 |
| 2009 | -.12 | 177 |
| 2008 | 4.02 | 103 |
| 2007 | 8.78 | 55 |
| 2006 | 7.95 | 52 |
| 2005 | 4.79 | 70 |
| 2004 | 4.11 | 68 |
| 2003 | 2.69 | 86 |
| 2002 | 1.68 | 113 |
| 2001 | 2.08 | 96 |
| 2000 | 4.08 | 66 |
| 1999 | 4.61 | 57 |
| 1998 | 4.97 | 44 |
| 1997 | 7.98 | 18 |
| 1996 | 6.39 | 18 |
| 1995 | 3.1 | 46 |