| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 26.8 | 72 |
| 2015 | 27.19 | 84 |
| 2014 | 27.78 | 75 |
| 2013 | 28.13 | 76 |
| 2012 | 27.21 | 82 |
| 2011 | 25.59 | 99 |
| 2010 | 24.23 | 107 |
| 2009 | 23.07 | 107 |
| 2008 | 24.1 | 107 |
| 2007 | 22.9 | 115 |
| 2006 | 23.06 | 115 |
| 2005 | 24.11 | 112 |
| 2004 | 24.36 | 113 |
| 2003 | 23.33 | 117 |
| 2002 | 24.3 | 108 |
| 2001 | 24.26 | 110 |
| 2000 | 22.99 | 118 |
| 1999 | 23.18 | 117 |
| 1998 | 22.05 | 121 |
| 1997 | 22.11 | 119 |
| 1996 | 22.57 | 115 |
| 1995 | 22.6 | 115 |
| 1994 | 22.17 | 101 |