| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 27.91 | 66 |
| 2015 | 27.36 | 81 |
| 2014 | 26.84 | 84 |
| 2013 | 26.91 | 87 |
| 2012 | 26.34 | 92 |
| 2011 | 27 | 93 |
| 2010 | 27.27 | 90 |
| 2009 | 27.55 | 80 |
| 2008 | 28.44 | 83 |
| 2007 | 27.37 | 90 |
| 2006 | 26.39 | 100 |
| 2005 | 25.98 | 99 |
| 2004 | 24.91 | 110 |
| 2003 | 23.39 | 116 |
| 2002 | 21.68 | 126 |
| 2001 | 23.14 | 119 |
| 2000 | 23.02 | 117 |
| 1999 | 29.66 | 67 |
| 1998 | 33.41 | 39 |
| 1997 | 30.72 | 64 |
| 1996 | 31.3 | 60 |
| 1995 | 25.7 | 99 |
| 1994 | 25.86 | 85 |