| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.93 | 17 |
| 2015 | 4.93 | 17 |
| 2014 | 4.98 | 18 |
| 2013 | 5.05 | 20 |
| 2012 | 5.12 | 21 |
| 2011 | 5.2 | 23 |
| 2010 | 5.26 | 24 |
| 2009 | 5.35 | 28 |
| 2008 | 5.44 | 29 |
| 2007 | 5.51 | 30 |
| 2006 | 5.56 | 33 |
| 2005 | 5.61 | 34 |
| 2004 | 5.69 | 39 |
| 2003 | 5.77 | 41 |
| 2002 | 5.83 | 44 |
| 2001 | 5.89 | 45 |
| 2000 | 5.93 | 48 |
| 1999 | 6.01 | 49 |
| 1998 | 6.09 | 49 |
| 1997 | 6.16 | 51 |
| 1996 | 6.21 | 55 |
| 1995 | 6.25 | 57 |
| 1994 | 6.34 | 59 |
| 1993 | 6.42 | 61 |
| 1992 | 6.48 | 63 |
| 1991 | 6.53 | 66 |
| 1990 | 6.55 | 68 |
| 1989 | 6.62 | 72 |
| 1988 | 6.68 | 78 |
| 1987 | 6.72 | 77 |
| 1986 | 6.73 | 77 |