| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.65 | 3 |
| 2015 | 5.78 | 3 |
| 2014 | 5.89 | 4 |
| 2013 | 6.01 | 5 |
| 2012 | 6.12 | 6 |
| 2011 | 6.23 | 5 |
| 2010 | 6.33 | 4 |
| 2009 | 6.45 | 4 |
| 2008 | 6.55 | 6 |
| 2007 | 6.63 | 6 |
| 2006 | 6.65 | 6 |
| 2005 | 6.65 | 5 |
| 2004 | 6.66 | 4 |
| 2003 | 6.66 | 4 |
| 2002 | 6.68 | 4 |
| 2001 | 6.69 | 4 |
| 2000 | 6.72 | 3 |
| 1999 | 6.72 | 4 |
| 1998 | 6.73 | 5 |
| 1997 | 5.78 | 8 |
| 1996 | 4.57 | 23 |
| 1995 | 4.55 | 25 |
| 1994 | 4.54 | 30 |
| 1993 | 4.53 | 33 |
| 1992 | 4.52 | 37 |
| 1991 | 4.51 | 44 |
| 1990 | 4.5 | 46 |
| 1989 | 4.48 | 51 |
| 1988 | 4.47 | 53 |
| 1987 | 4.46 | 59 |
| 1986 | 6.55 | 20 |