| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.56 | 27 |
| 2015 | 2.54 | 33 |
| 2014 | 2.34 | 37 |
| 2013 | 2.36 | 36 |
| 2012 | 2.41 | 34 |
| 2011 | 2.48 | 31 |
| 2010 | 2.73 | 34 |
| 2009 | 3.22 | 29 |
| 2008 | 2.98 | 30 |
| 2007 | 2.68 | 33 |
| 2006 | 2.78 | 31 |
| 2005 | 2.84 | 30 |
| 2004 | 2.61 | 39 |
| 2003 | 2.49 | 42 |
| 2002 | 3.08 | 34 |
| 2001 | 3.25 | 31 |
| 2000 | 3.47 | 29 |
| 1999 | 3.36 | 30 |
| 1998 | 3.34 | 31 |
| 1997 | 3.19 | 35 |
| 1996 | 3.16 | 32 |
| 1995 | 3.05 | 34 |
| 1994 | 3.08 | 36 |
| 1993 | 3.09 | 39 |
| 1992 | 3.12 | 39 |
| 1991 | 2.99 | 46 |
| 1990 | 3.26 | 47 |
| 1989 | 3.23 | 44 |
| 1988 | 3.61 | 35 |
| 1987 | 3.65 | 39 |
| 1986 | 3.55 | 39 |