| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.11 | 22 |
| 2015 | 4.13 | 27 |
| 2014 | 4.15 | 30 |
| 2013 | 4.14 | 31 |
| 2012 | 4.11 | 31 |
| 2011 | 4.05 | 34 |
| 2010 | 3.99 | 35 |
| 2009 | 3.93 | 37 |
| 2008 | 3.89 | 40 |
| 2007 | 3.86 | 41 |
| 2006 | 3.85 | 44 |
| 2005 | 3.84 | 42 |
| 2004 | 3.83 | 47 |
| 2003 | 3.83 | 46 |
| 2002 | 3.87 | 45 |
| 2001 | 3.19 | 63 |
| 2000 | 1.51 | 128 |
| 1999 | 1.58 | 118 |
| 1998 | 1.61 | 116 |
| 1997 | 1.59 | 123 |
| 1996 | 1.51 | 129 |
| 1995 | 1.42 | 131 |
| 1994 | 1.34 | 133 |
| 1993 | 1.3 | 138 |
| 1992 | 1.32 | 136 |
| 1991 | 1.55 | 134 |
| 1990 | 2.57 | 102 |
| 1989 | 2.65 | 106 |
| 1988 | 2.73 | 104 |
| 1987 | 2.83 | 106 |
| 1986 | 2.93 | 103 |