| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 9.98 | 129 |
| 2015 | 9.7 | 127 |
| 2014 | 9.9 | 125 |
| 2013 | 9.23 | 117 |
| 2012 | 8.99 | 114 |
| 2011 | 8.91 | 115 |
| 2010 | 9.1 | 119 |
| 2009 | 9.1 | 115 |
| 2008 | 9.6 | 138 |
| 2007 | 9.8 | 139 |
| 2006 | 9.67 | 131 |
| 2005 | 11.01 | 135 |
| 2004 | 10.83 | 132 |
| 2003 | 11.92 | 138 |
| 2002 | 11.59 | 130 |
| 2001 | 12.46 | 138 |
| 2000 | 13.6 | 143 |
| 1999 | 13.94 | 149 |
| 1998 | 19.12 | 171 |
| 1997 | 16.9 | 164 |
| 1996 | 18.1 | 165 |
| 1995 | 22.9 | 180 |
| 1994 | 19.58 | 169 |
| 1993 | 15.9 | 152 |
| 1992 | 16 | 155 |
| 1991 | 17.3 | 160 |