| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5 | 110 |
| 2015 | 5 | 120 |
| 2014 | 5 | 129 |
| 2013 | 5 | 136 |
| 2012 | 5 | 139 |
| 2011 | 5 | 140 |
| 2010 | 5 | 142 |
| 2009 | 5 | 144 |
| 2008 | 5 | 145 |
| 2007 | 6.75 | 135 |
| 2006 | 7.75 | 119 |
| 2005 | 7.75 | 111 |
| 2004 | 5 | 147 |
| 2003 | 5 | 144 |
| 2002 | 5 | 143 |
| 2001 | 5.125 | 144 |
| 2000 | 9.5 | 114 |
| 1999 | 8.5 | 124 |
| 1998 | 9 | 119 |
| 1997 | 9.5 | 113 |
| 1996 | 8.5 | 120 |
| 1995 | 8.75 | 116 |
| 1994 | 8.5 | 110 |
| 1993 | 6.5 | 116 |
| 1992 | 6.5 | 109 |
| 1991 | 8.5 | 100 |
| 1990 | 10 | 87 |