| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 4.84 | 46 |
| 2014 | 7.18 | 23 |
| 2013 | 6.47 | 36 |
| 2012 | 5.47 | 54 |
| 2011 | 5.46 | 43 |
| 2010 | 8.4 | 24 |
| 2009 | 4.63 | 77 |
| 2008 | 6.31 | 50 |
| 2007 | 9.08 | 31 |
| 2006 | 2.95 | 92 |
| 2005 | 0.68 | 117 |
| 2004 | 3.88 | 65 |
| 2003 | 3.44 | 64 |
| 2002 | 3.48 | 70 |
| 2001 | 5.53 | 46 |
| 2000 | 6.39 | 33 |
| 1999 | 6.74 | 32 |
| 1998 | 5.79 | 35 |
| 1997 | 1.75 | 82 |
| 1996 | 3.49 | 54 |
| 1995 | 5.71 | 27 |
| 1994 | -3.03 | 99 |
| 1993 | -4.98 | 103 |
| 1992 | -16.8 | 110 |
| 1991 | 9.2 | 20 |
| 1990 | 13 | 7 |
| 1989 | -2.5 | 86 |
| 1988 | -13.3 | 91 |
| 1987 | 1.8 | 56 |
| 1986 | 27.8 | 3 |