| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.02 | 34 |
| 2015 | 2.95 | 87 |
| 2014 | 3.63 | 77 |
| 2013 | 0.15 | 170 |
| 2012 | 1.47 | 144 |
| 2011 | 3.5 | 97 |
| 2010 | 3.84 | 78 |
| 2009 | 3.19 | 90 |
| 2008 | 2.73 | 127 |
| 2007 | 5.83 | 88 |
| 2006 | 6.23 | 72 |
| 2005 | 3.61 | 87 |
| 2004 | 5.44 | 51 |
| 2003 | 2.47 | 92 |
| 2002 | 2.06 | 108 |
| 2001 | 2.98 | 78 |
| 2000 | 5.43 | 47 |
| 1999 | 4.28 | 63 |
| 1998 | 3.65 | 60 |
| 1997 | 3.08 | 64 |
| 1996 | 2.81 | 47 |
| 1995 | 2.57 | 52 |
| 1994 | 1.69 | 61 |
| 1993 | 1.79 | 50 |
| 1992 | 0.72 | 78 |
| 1991 | 0.34 | 99 |
| 1990 | 0.13 | 114 |