| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 6.61 | 20 |
| 2015 | 3.18 | 65 |
| 2014 | 5.34 | 47 |
| 2013 | 4.93 | 63 |
| 2012 | 6.1 | 53 |
| 2011 | 5.02 | 86 |
| 2010 | 3.6 | 86 |
| 2009 | 7.38 | 36 |
| 2008 | 10.72 | 63 |
| 2007 | 8.01 | 50 |
| 2006 | 6.07 | 75 |
| 2005 | 3.44 | 102 |
| 2004 | 5.02 | 63 |
| 2003 | 6.63 | 53 |
| 2002 | 33.81 | 6 |
| 2001 | -9.62 | 170 |
| 2000 | 6.13 | 54 |
| 1996 | 9.33 | 65 |
| 1995 | 9.27 | 81 |
| 1994 | 8.21 | 89 |
| 1993 | 13.14 | 52 |
| 1992 | 17.21 | 38 |
| 1991 | 17.68 | 46 |
| 1990 | 11.63 | 55 |
| 1989 | 14.73 | 39 |
| 1988 | 11.46 | 48 |
| 1987 | 11.75 | 43 |
| 1986 | 18 | 34 |