| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 8.115 | 70 |
| 2015 | 8.477 | 79 |
| 2014 | 8.99 | 78 |
| 2013 | 9.01 | 85 |
| 2012 | 8.781 | 89 |
| 2011 | 8.713 | 92 |
| 2010 | 9.024 | 93 |
| 2009 | 9.247 | 97 |
| 2008 | 9.028 | 98 |
| 2007 | 8.677 | 106 |
| 2006 | 8.178 | 108 |
| 2005 | 7.607 | 112 |
| 2004 | 8.257 | 106 |
| 2003 | 9.297 | 99 |
| 2002 | 10.179 | 99 |
| 2001 | 10.936 | 98 |
| 2000 | 11.799 | 93 |
| 1999 | 12.326 | 95 |
| 1998 | 12.609 | 94 |
| 1997 | 12.25 | 90 |
| 1996 | 11.248 | 99 |
| 1995 | 10.663 | 103 |
| 1994 | 10.445 | 94 |
| 1993 | 10.23 | 93 |
| 1992 | 10.16 | 88 |
| 1991 | 10.37 | 82 |
| 1990 | 10.31 | 82 |