| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 8 | 72 |
| 2015 | 8 | 85 |
| 2014 | 8 | 91 |
| 2013 | 8 | 97 |
| 2012 | 8 | 100 |
| 2011 | 8 | 96 |
| 2010 | 8 | 99 |
| 2009 | 8 | 107 |
| 2008 | 8 | 114 |
| 2007 | 8 | 118 |
| 2006 | 8 | 113 |
| 2005 | 8 | 106 |
| 2004 | 8 | 108 |
| 2003 | 8.125 | 109 |
| 2002 | 8.583 | 108 |
| 2001 | 9.5 | 107 |
| 2000 | 10 | 110 |
| 1999 | 10.75 | 109 |
| 1998 | 11.5 | 101 |
| 1997 | 15.708 | 70 |
| 1996 | 19 | 63 |
| 1995 | 18.417 | 54 |
| 1994 | 16 | 58 |