| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 0.77 | 156 |
| 2014 | 0.59 | 165 |
| 2013 | 0.64 | 158 |
| 2012 | 1.87 | 127 |
| 2011 | 1.93 | 133 |
| 2010 | 3.06 | 96 |
| 2009 | 1.84 | 126 |
| 2008 | 3.21 | 117 |
| 2007 | 1.08 | 168 |
| 2006 | 3.68 | 106 |
| 2005 | -1.44 | 183 |
| 2004 | 2.51 | 101 |
| 2003 | -2.74 | 185 |
| 2002 | 6.49 | 30 |
| 2001 | 1.9 | 103 |
| 2000 | 5.22 | 51 |
| 1999 | 6.35 | 40 |
| 1998 | 9.68 | 16 |
| 1997 | -.89 | 174 |
| 1996 | 1.35 | 89 |
| 1995 | 3.05 | 47 |
| 1994 | 4.46 | 21 |
| 1993 | 5.3 | 23 |
| 1992 | 6.8 | 9 |
| 1991 | 7.1 | 10 |
| 1990 | 2.7 | 30 |
| 1989 | 9.64 | 5 |
| 1988 | 7.31 | 7 |
| 1987 | 9.64 | 6 |
| 1986 | 6.93 | 5 |