| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 8.895 | 63 |
| 2015 | 9.038 | 70 |
| 2014 | 7.62 | 94 |
| 2013 | 6.657 | 106 |
| 2012 | 6.112 | 112 |
| 2011 | 5.881 | 120 |
| 2010 | 5.387 | 128 |
| 2009 | 4.275 | 150 |
| 2008 | 6.753 | 128 |
| 2007 | 6.522 | 139 |
| 2006 | 5.527 | 144 |
| 2005 | 2.648 | 164 |
| 2004 | 2.566 | 156 |
| 2003 | 2.846 | 153 |
| 2002 | 3.833 | 151 |
| 2001 | 4.836 | 147 |
| 2000 | 4.771 | 147 |
| 1999 | 3.343 | 150 |
| 1998 | 6.219 | 139 |
| 1997 | 6.57 | 129 |
| 1996 | 5.849 | 135 |
| 1995 | 6.558 | 129 |
| 1994 | 6.135 | 123 |
| 1993 | 9.931 | 98 |
| 1992 | 12.657 | 75 |
| 1991 | 10.625 | 81 |
| 1990 | 11.292 | 75 |
| 1989 | 9.417 | 90 |
| 1988 | 8.292 | 93 |
| 1987 | 11.146 | 63 |
| 1986 | 12.229 | 55 |