| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 8.59 | 22 |
| 2014 | 6.79 | 37 |
| 2013 | 5.67 | 52 |
| 2012 | 4.87 | 53 |
| 2011 | 1.56 | 129 |
| 2010 | 0.51 | 142 |
| 2009 | -2.48 | 90 |
| 2008 | 1.22 | 113 |
| 2007 | -1.4 | 148 |
| 2006 | 1.81 | 133 |
| 2005 | -.91 | 152 |
| 2004 | -.22 | 153 |
| 2003 | 0.54 | 134 |
| 2002 | 0.77 | 117 |
| 2001 | 1.01 | 106 |
| 2000 | 2.05 | 116 |
| 1999 | 5.96 | 50 |
| 1998 | 9.37 | 25 |
| 1997 | 6.44 | 53 |
| 1996 | 0.85 | 116 |
| 1995 | -2.33 | 114 |
| 1994 | -3.21 | 112 |
| 1993 | -9.94 | 113 |
| 1992 | -10.4 | 115 |
| 1991 | -6.6 | 109 |
| 1990 | -6.8 | 109 |
| 1989 | -2.3 | 100 |
| 1988 | -7.09 | 105 |
| 1987 | 0.51 | 82 |
| 1986 | 6.09 | 39 |