| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 31.59 | 121 |
| 2015 | 28.75 | 129 |
| 2014 | 26.84 | 137 |
| 2013 | 23.97 | 147 |
| 2012 | 28.13 | 135 |
| 2011 | 30.14 | 127 |
| 2010 | 34.39 | 106 |
| 2009 | 35.98 | 100 |
| 2008 | 38.7 | 91 |
| 2007 | 38.25 | 97 |
| 2006 | 39.61 | 88 |
| 2005 | 38.78 | 92 |
| 2004 | 40.33 | 78 |
| 2003 | 39.25 | 83 |
| 2002 | 38.46 | 95 |
| 2001 | 40.66 | 82 |
| 2000 | 39.33 | 92 |
| 1999 | 35.7 | 116 |
| 1998 | 37.14 | 109 |
| 1997 | 34.05 | 136 |
| 1996 | 30.69 | 146 |
| 1995 | 35.29 | 132 |
| 1994 | 37.05 | 121 |
| 1993 | 36.3 | 126 |
| 1992 | 29.31 | 156 |
| 1991 | 37.04 | 128 |