| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 10.84 | 134 |
| 2015 | 11.08 | 138 |
| 2014 | 11.49 | 138 |
| 2013 | 11.5 | 135 |
| 2012 | 12.2 | 138 |
| 2011 | 13.3 | 144 |
| 2010 | 8.2 | 102 |
| 2009 | 9.3 | 122 |
| 2008 | 8.99 | 129 |
| 2007 | 8.3 | 114 |
| 2006 | 7.4 | 98 |
| 2005 | 7 | 79 |
| 2004 | 7.7 | 88 |
| 2003 | 9.42 | 113 |
| 2002 | 11.4 | 128 |
| 2001 | 13.3 | 145 |
| 2000 | 15.3 | 155 |
| 1999 | 14.6 | 155 |
| 1998 | 7.7 | 91 |
| 1997 | 9.6 | 110 |
| 1996 | 8.3 | 95 |
| 1995 | 7.9 | 92 |
| 1994 | 7.6 | 89 |
| 1993 | 5.5 | 63 |
| 1992 | 3.9 | 42 |
| 1991 | 3.5 | 41 |