| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.05 | 18 |
| 2015 | 5.07 | 21 |
| 2014 | 5.13 | 23 |
| 2013 | 5.21 | 27 |
| 2012 | 5.32 | 29 |
| 2011 | 5.42 | 31 |
| 2010 | 5.5 | 31 |
| 2009 | 5.58 | 33 |
| 2008 | 5.62 | 32 |
| 2007 | 5.64 | 34 |
| 2006 | 5.64 | 35 |
| 2005 | 5.65 | 37 |
| 2004 | 5.69 | 40 |
| 2003 | 5.73 | 38 |
| 2002 | 5.76 | 40 |
| 2001 | 5.78 | 41 |
| 2000 | 5.77 | 41 |
| 1999 | 5.83 | 43 |
| 1998 | 5.88 | 44 |
| 1997 | 5.91 | 42 |
| 1996 | 5.93 | 42 |
| 1995 | 5.91 | 42 |
| 1994 | 5.94 | 44 |
| 1993 | 5.95 | 46 |
| 1992 | 5.94 | 46 |
| 1991 | 5.92 | 46 |
| 1990 | 5.9 | 46 |
| 1989 | 5.96 | 48 |
| 1988 | 6.02 | 48 |
| 1987 | 6.1 | 53 |
| 1986 | 6.16 | 56 |