| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.61 | 4 |
| 2015 | 5.55 | 4 |
| 2014 | 5.48 | 5 |
| 2013 | 5.46 | 10 |
| 2012 | 5.52 | 8 |
| 2011 | 5.62 | 8 |
| 2010 | 5.74 | 7 |
| 2009 | 5.83 | 7 |
| 2008 | 5.92 | 7 |
| 2007 | 5.92 | 7 |
| 2006 | 5.89 | 7 |
| 2005 | 5.85 | 9 |
| 2004 | 5.81 | 11 |
| 2003 | 5.66 | 13 |
| 2002 | 5.37 | 12 |
| 2001 | 4.97 | 14 |
| 2000 | 4.5 | 20 |
| 1999 | 4.08 | 32 |
| 1998 | 3.95 | 37 |
| 1997 | 3.91 | 42 |
| 1996 | 4.07 | 41 |
| 1995 | 4.3 | 30 |
| 1994 | 4.48 | 32 |
| 1993 | 4.69 | 31 |
| 1992 | 4.91 | 31 |
| 1991 | 5.2 | 24 |
| 1990 | 6.17 | 13 |
| 1989 | 6.42 | 15 |
| 1988 | 6.6 | 11 |
| 1987 | 6.65 | 15 |
| 1986 | 6.61 | 19 |