| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 25.27 | 29 |
| 2015 | 26.47 | 45 |
| 2014 | 26 | 48 |
| 2013 | 23.75 | 65 |
| 2012 | 24.02 | 64 |
| 2011 | 22.96 | 68 |
| 2010 | 19.17 | 84 |
| 2009 | 20.44 | 79 |
| 2008 | 22.62 | 70 |
| 2007 | 21.82 | 71 |
| 2006 | 19.3 | 80 |
| 2005 | 19.68 | 78 |
| 2004 | 19.76 | 70 |
| 2003 | 18.64 | 72 |
| 2002 | 16.65 | 84 |
| 2001 | 18.24 | 70 |
| 2000 | 19.03 | 62 |
| 1999 | 17.34 | 68 |
| 1998 | 14.65 | 81 |
| 1997 | 12.92 | 88 |
| 1996 | 13.03 | 85 |