| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 2.26 | 104 |
| 2014 | 1.22 | 144 |
| 2013 | 3.79 | 76 |
| 2012 | 3.24 | 91 |
| 2011 | 0.67 | 166 |
| 2010 | 4.32 | 66 |
| 2009 | 2.28 | 113 |
| 2008 | 2.94 | 123 |
| 2007 | 3.28 | 122 |
| 2006 | 4.02 | 101 |
| 2005 | 4.34 | 77 |
| 2004 | 3.39 | 86 |
| 2003 | 3.44 | 66 |
| 2002 | 2.49 | 95 |
| 2001 | 4.21 | 53 |
| 2000 | 2.66 | 98 |
| 1999 | 4.82 | 54 |
| 1998 | 6.43 | 34 |
| 1997 | 2.59 | 73 |
| 1996 | 1.28 | 92 |
| 1995 | 1.22 | 87 |
| 1994 | 0.93 | 93 |
| 1993 | 1.4 | 65 |
| 1992 | 1.9 | 42 |
| 1991 | 2.05 | 41 |
| 1990 | 2.86 | 28 |
| 1989 | 2.46 | 29 |
| 1988 | 1.79 | 34 |
| 1987 | 0.7 | 63 |
| 1986 | 0.61 | 59 |