| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 9.42 | 22 |
| 2014 | 10.31 | 18 |
| 2013 | 8.71 | 25 |
| 2012 | 10.26 | 25 |
| 2011 | 6.2 | 54 |
| 2010 | 6.54 | 49 |
| 2009 | 4.91 | 65 |
| 2008 | 7.87 | 57 |
| 2007 | 10.04 | 41 |
| 2006 | 6.64 | 63 |
| 2005 | 5.99 | 54 |
| 2004 | 2.46 | 103 |
| 2003 | 1.75 | 120 |
| 2002 | 3.06 | 83 |
| 2001 | 3.68 | 63 |
| 2000 | 3.24 | 88 |
| 1999 | 6.6 | 39 |
| 1998 | 7.78 | 25 |
| 1997 | 5.92 | 28 |
| 1996 | 8.37 | 12 |
| 1995 | 4.38 | 33 |
| 1994 | 2.47 | 43 |
| 1993 | 2.14 | 41 |