| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 25.41 | 51 |
| 2014 | 20.41 | 70 |
| 2013 | 21.13 | 75 |
| 2012 | 20.87 | 79 |
| 2011 | 21.24 | 76 |
| 2010 | 22.82 | 67 |
| 2009 | 22.61 | 67 |
| 2008 | 19.72 | 83 |
| 2007 | 18.94 | 89 |
| 2006 | 19.85 | 77 |
| 2005 | 20.92 | 72 |
| 2004 | 23.92 | 57 |
| 2003 | 20.66 | 63 |
| 2002 | 21.35 | 58 |
| 2001 | 22.27 | 54 |
| 2000 | 24.73 | 44 |
| 1999 | 21.36 | 53 |
| 1998 | 16.84 | 70 |
| 1997 | 14.5 | 78 |
| 1996 | 15.02 | 76 |
| 1995 | 9.76 | 107 |
| 1994 | 8.61 | 111 |