| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.06 | 25 |
| 2015 | 4.11 | 28 |
| 2014 | 4.18 | 29 |
| 2013 | 4.3 | 29 |
| 2012 | 4.49 | 22 |
| 2011 | 4.74 | 17 |
| 2010 | 5.02 | 14 |
| 2009 | 5.28 | 13 |
| 2008 | 5.51 | 13 |
| 2007 | 5.66 | 9 |
| 2006 | 5.76 | 8 |
| 2005 | 5.83 | 10 |
| 2004 | 5.86 | 10 |
| 2003 | 5.89 | 10 |
| 2002 | 5.99 | 7 |
| 2001 | 6.11 | 7 |
| 2000 | 6.26 | 5 |
| 1999 | 6.38 | 5 |
| 1998 | 6.54 | 6 |
| 1997 | 6.73 | 4 |
| 1996 | 6.95 | 2 |
| 1995 | 5.39 | 8 |
| 1994 | 4.68 | 25 |
| 1993 | 4.84 | 28 |
| 1992 | 4.95 | 29 |
| 1991 | 5.03 | 30 |
| 1990 | 5.08 | 30 |
| 1989 | 5.12 | 31 |
| 1988 | 5.15 | 36 |
| 1987 | 5.13 | 43 |
| 1986 | 5.09 | 45 |