| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.47 | 29 |
| 2015 | 2.41 | 36 |
| 2014 | 2.5 | 35 |
| 2013 | 2.47 | 33 |
| 2012 | 2.54 | 32 |
| 2011 | 2.65 | 29 |
| 2010 | 2.79 | 31 |
| 2009 | 2.98 | 35 |
| 2008 | 2.63 | 37 |
| 2007 | 2.42 | 39 |
| 2006 | 2.61 | 37 |
| 2005 | 2.84 | 29 |
| 2004 | 2.92 | 30 |
| 2003 | 2.76 | 35 |
| 2002 | 2.92 | 36 |
| 2001 | 3.02 | 36 |
| 2000 | 3.04 | 33 |
| 1999 | 3.05 | 34 |
| 1998 | 2.81 | 38 |
| 1997 | 2.73 | 44 |
| 1996 | 2.55 | 44 |
| 1995 | 2.66 | 45 |
| 1994 | 2.75 | 43 |
| 1993 | 2.91 | 42 |
| 1992 | 2.79 | 47 |
| 1991 | 3 | 45 |
| 1990 | 3.24 | 48 |
| 1989 | 3.53 | 36 |
| 1988 | 3.73 | 34 |
| 1987 | 3.95 | 32 |
| 1986 | 3.83 | 31 |