| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.91 | 25 |
| 2015 | 3.06 | 47 |
| 2014 | 2.47 | 52 |
| 2013 | 0.39 | 111 |
| 2012 | 0.75 | 104 |
| 2011 | 3.09 | 62 |
| 2010 | 3.04 | 62 |
| 2009 | 3.52 | 26 |
| 2008 | 6.74 | 27 |
| 2007 | 5.71 | 51 |
| 2006 | 4.87 | 54 |
| 2005 | 1.82 | 109 |
| 2004 | 4.31 | 59 |
| 2003 | 1.66 | 84 |
| 2002 | 3.98 | 42 |
| 2001 | 2.03 | 64 |
| 2000 | 3.96 | 35 |
| 1999 | 5.52 | 22 |
| 1998 | 4.83 | 36 |
| 1997 | 7.27 | 18 |
| 1996 | 8.48 | 17 |
| 1995 | 3.03 | 47 |
| 1994 | 4.27 | 26 |
| 1993 | 5.09 | 23 |
| 1992 | 2.06 | 41 |
| 1991 | 6.24 | 19 |