| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 9.88 | 126 |
| 2015 | 9.87 | 129 |
| 2014 | 10.85 | 135 |
| 2013 | 11.87 | 139 |
| 2012 | 15.05 | 158 |
| 2011 | 16.21 | 161 |
| 2010 | 19.48 | 171 |
| 2009 | 17.51 | 168 |
| 2008 | 7.74 | 114 |
| 2007 | 6.05 | 75 |
| 2006 | 7.03 | 90 |
| 2005 | 10.03 | 126 |
| 2004 | 11.71 | 139 |
| 2003 | 12.06 | 140 |
| 2002 | 13.83 | 146 |
| 2001 | 13.82 | 148 |
| 2000 | 14.21 | 149 |
| 1999 | 13.79 | 145 |
| 1998 | 14.46 | 154 |
| 1997 | 14.7 | 153 |
| 1996 | 20.93 | 175 |
| 1995 | 8.1 | 95 |
| 1994 | 15.38 | 150 |
| 1993 | 17.94 | 161 |
| 1992 | 14.1 | 142 |
| 1991 | 17.67 | 162 |