| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 29.22 | 53 |
| 2015 | 28.43 | 68 |
| 2014 | 27.76 | 76 |
| 2013 | 28.86 | 68 |
| 2012 | 25.62 | 97 |
| 2011 | 30.85 | 59 |
| 2010 | 29.26 | 68 |
| 2009 | 26.56 | 92 |
| 2008 | 23.52 | 110 |
| 2007 | 19.29 | 139 |
| 2006 | 20.06 | 134 |
| 2005 | 22.39 | 119 |
| 2004 | 24.13 | 116 |
| 2003 | 22.32 | 126 |
| 2002 | 23.34 | 118 |
| 2001 | 28.93 | 74 |
| 2000 | 31.39 | 61 |
| 1999 | 24.98 | 101 |
| 1998 | 22.76 | 116 |
| 1997 | 22.81 | 117 |
| 1996 | 18.29 | 132 |
| 1995 | 19.54 | 129 |
| 1994 | 25.45 | 87 |
| 1993 | 32 | 55 |
| 1992 | 37.79 | 33 |
| 1991 | 35.46 | 43 |
| 1990 | 35.02 | 36 |