| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2014 | 9.1 | 165 |
| 2013 | 8.8 | 171 |
| 2012 | 8.42 | 171 |
| 2011 | 10.89 | 168 |
| 2010 | 13.72 | 164 |
| 2009 | 12.44 | 165 |
| 2008 | 10.25 | 170 |
| 2007 | 8.99 | 172 |
| 2006 | 9.18 | 170 |
| 2005 | 8.92 | 169 |
| 2004 | 8.58 | 173 |
| 2003 | 9.24 | 171 |
| 2002 | 10.13 | 167 |
| 2001 | 10.35 | 167 |
| 2000 | 12.8 | 159 |
| 1999 | 9.56 | 160 |
| 1998 | 9.16 | 160 |
| 1997 | 9.07 | 159 |
| 1996 | 10.59 | 155 |
| 1995 | 12.24 | 153 |
| 1994 | 12.7 | 135 |
| 1993 | 10.05 | 135 |
| 1992 | 10.9 | 132 |
| 1991 | 12.72 | 125 |
| 1990 | 14.09 | 121 |
| 1989 | 12.91 | 107 |
| 1988 | 13.18 | 102 |
| 1987 | 13.35 | 102 |
| 1986 | 10.21 | 103 |