| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 10.5 | 159 |
| 2014 | 7.54 | 168 |
| 2013 | 5.76 | 176 |
| 2012 | 6.28 | 174 |
| 2011 | 6.51 | 177 |
| 2010 | 7.36 | 176 |
| 2009 | 10.68 | 168 |
| 2008 | 16.74 | 153 |
| 2007 | 18.79 | 143 |
| 2006 | 19.47 | 135 |
| 2005 | 14.87 | 159 |
| 2004 | 11.78 | 166 |
| 2003 | 12.3 | 163 |
| 2002 | 11.67 | 164 |
| 2001 | 12.42 | 161 |
| 2000 | 14.14 | 158 |
| 1999 | 15.65 | 147 |
| 1998 | 15.54 | 145 |
| 1997 | 14.32 | 151 |
| 1996 | 14.21 | 148 |
| 1995 | 14.78 | 144 |
| 1994 | 16.07 | 123 |
| 1993 | 17.24 | 112 |
| 1992 | 19.23 | 104 |
| 1991 | 20.58 | 101 |