| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.36 | 43 |
| 2015 | 3.4 | 44 |
| 2014 | 3.43 | 47 |
| 2013 | 3.47 | 48 |
| 2012 | 3.52 | 47 |
| 2011 | 3.56 | 49 |
| 2010 | 3.6 | 49 |
| 2009 | 3.63 | 44 |
| 2008 | 3.67 | 46 |
| 2007 | 3.7 | 49 |
| 2006 | 3.74 | 48 |
| 2005 | 3.79 | 46 |
| 2004 | 3.84 | 46 |
| 2003 | 3.83 | 47 |
| 2002 | 3.71 | 50 |
| 2001 | 3.54 | 53 |
| 2000 | 3.38 | 59 |
| 1999 | 3.27 | 61 |
| 1998 | 3.21 | 63 |
| 1997 | 3.31 | 63 |
| 1996 | 3.57 | 55 |
| 1995 | 3.9 | 47 |
| 1994 | 4.2 | 42 |
| 1993 | 4.39 | 38 |
| 1992 | 4.42 | 43 |
| 1991 | 4.29 | 51 |
| 1990 | 4.13 | 57 |
| 1989 | 4.8 | 38 |
| 1988 | 4.82 | 43 |
| 1987 | 4.77 | 48 |
| 1986 | 4.78 | 53 |