| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 50.56 | 75 |
| 2015 | 43.44 | 103 |
| 2014 | 47.85 | 85 |
| 2013 | 49.34 | 81 |
| 2012 | 45.64 | 86 |
| 2011 | 48.67 | 76 |
| 2010 | 47.97 | 85 |
| 2009 | 43.7 | 92 |
| 2008 | 34.63 | 107 |
| 2007 | 48.45 | 78 |
| 2006 | 38.15 | 97 |
| 2005 | 37.49 | 98 |
| 2004 | 35.87 | 94 |
| 2003 | 38.45 | 88 |
| 2002 | 30.33 | 103 |
| 2001 | 23.79 | 117 |
| 2000 | 21.14 | 119 |
| 1999 | 20.38 | 119 |
| 1998 | 17.69 | 127 |
| 1997 | 18.23 | 127 |
| 1996 | 16.21 | 128 |
| 1995 | 15.66 | 133 |
| 1994 | 20.14 | 121 |
| 1993 | 18.78 | 123 |
| 1992 | 23.25 | 103 |
| 1991 | 43.87 | 53 |