| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 9.73 | 61 |
| 2015 | 10.27 | 117 |
| 2014 | 9.05 | 135 |
| 2013 | 8.9 | 150 |
| 2012 | 7.89 | 153 |
| 2011 | 7.36 | 159 |
| 2010 | 8.16 | 155 |
| 2009 | 8.93 | 153 |
| 2008 | 8.11 | 154 |
| 2007 | 8.04 | 152 |
| 2006 | 8.28 | 150 |
| 2005 | 9.07 | 146 |
| 2004 | 9.68 | 135 |
| 2003 | 10.69 | 124 |
| 2002 | 11.32 | 120 |
| 2001 | 10.93 | 121 |
| 2000 | 10.64 | 121 |
| 1999 | 12.56 | 100 |
| 1998 | 10.71 | 110 |
| 1997 | 8.42 | 126 |
| 1996 | 8.16 | 126 |
| 1995 | 7.78 | 125 |
| 1994 | 6.04 | 122 |