| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 28.59 | 39 |
| 2014 | 28.76 | 43 |
| 2013 | 29.55 | 50 |
| 2012 | 34.98 | 38 |
| 2011 | 29.43 | 48 |
| 2010 | 29.23 | 47 |
| 2009 | 29.52 | 43 |
| 2008 | 33.39 | 41 |
| 2007 | 33.9 | 41 |
| 2006 | 29.58 | 44 |
| 2005 | 22.34 | 65 |
| 2004 | 19.55 | 73 |
| 2003 | 16.56 | 85 |
| 2002 | 18 | 76 |
| 2001 | 13.61 | 97 |
| 2000 | 15.35 | 79 |
| 1999 | 17.62 | 66 |
| 1998 | 14.49 | 83 |
| 1997 | 12.23 | 94 |
| 1996 | 15.35 | 74 |
| 1995 | 14.1 | 77 |
| 1994 | 6.17 | 121 |
| 1993 | 2.93 | 134 |