| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.23 | 17 |
| 2015 | 2.27 | 19 |
| 2014 | 2.3 | 20 |
| 2013 | 2.31 | 19 |
| 2012 | 2.29 | 21 |
| 2011 | 2.25 | 27 |
| 2010 | 2.19 | 33 |
| 2009 | 2.13 | 31 |
| 2008 | 2.08 | 37 |
| 2007 | 2.06 | 42 |
| 2006 | 2.05 | 42 |
| 2005 | 2.04 | 39 |
| 2004 | 2.03 | 41 |
| 2003 | 2.04 | 43 |
| 2002 | 2.07 | 40 |
| 2001 | 2.5 | 26 |
| 2000 | 3.51 | 10 |
| 1999 | 3.58 | 9 |
| 1998 | 3.61 | 8 |
| 1997 | 3.58 | 9 |
| 1996 | 3.51 | 8 |
| 1995 | 3.42 | 11 |
| 1994 | 3.34 | 11 |
| 1993 | 3.3 | 11 |
| 1992 | 3.32 | 9 |
| 1991 | 3.3 | 10 |
| 1990 | 2.78 | 24 |
| 1989 | 2.86 | 22 |
| 1988 | 2.94 | 21 |
| 1987 | 3.04 | 19 |
| 1986 | 3.13 | 16 |