| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.61 | 69 |
| 2015 | 2.7 | 69 |
| 2014 | 2.82 | 66 |
| 2013 | 2.93 | 64 |
| 2012 | 3.06 | 62 |
| 2011 | 3.18 | 59 |
| 2010 | 3.26 | 56 |
| 2009 | 3.34 | 53 |
| 2008 | 3.43 | 54 |
| 2007 | 3.51 | 55 |
| 2006 | 3.67 | 49 |
| 2005 | 3.88 | 41 |
| 2004 | 3.98 | 37 |
| 2003 | 4.08 | 35 |
| 2002 | 4.2 | 33 |
| 2001 | 4.06 | 36 |
| 2000 | 3.65 | 49 |
| 1999 | 3.77 | 43 |
| 1998 | 3.91 | 40 |
| 1997 | 4.01 | 39 |
| 1996 | 4.09 | 39 |
| 1995 | 4.16 | 33 |
| 1994 | 4.25 | 38 |
| 1993 | 4.3 | 42 |
| 1992 | 4.43 | 42 |
| 1991 | 4.6 | 40 |
| 1990 | 4.31 | 52 |
| 1989 | 4.4 | 52 |
| 1988 | 4.51 | 51 |
| 1987 | 4.53 | 57 |
| 1986 | 4.44 | 62 |