| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.57 | 10 |
| 2015 | 2.76 | 8 |
| 2014 | 2.94 | 9 |
| 2013 | 3.04 | 8 |
| 2012 | 3 | 10 |
| 2011 | 2.88 | 11 |
| 2010 | 2.69 | 17 |
| 2009 | 2.48 | 18 |
| 2008 | 2.33 | 24 |
| 2007 | 2.3 | 30 |
| 2006 | 2.35 | 26 |
| 2005 | 2.42 | 21 |
| 2004 | 2.48 | 22 |
| 2003 | 2.55 | 23 |
| 2002 | 2.62 | 21 |
| 2001 | 2.7 | 17 |
| 2000 | 2.79 | 17 |
| 1999 | 2.88 | 18 |
| 1998 | 3.17 | 13 |
| 1997 | 3.73 | 7 |
| 1996 | 3.7 | 7 |
| 1995 | 3.67 | 8 |
| 1994 | 3.63 | 8 |
| 1993 | 3.56 | 8 |
| 1992 | 3.44 | 8 |
| 1991 | 3.28 | 11 |
| 1990 | 3.09 | 14 |
| 1989 | 2.92 | 17 |
| 1988 | 2.01 | 54 |
| 1987 | 0.15 | 134 |
| 1986 | 0.25 | 130 |