| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | -.79 | 113 |
| 2015 | -.87 | 155 |
| 2014 | 2.89 | 84 |
| 2013 | 4.83 | 65 |
| 2012 | 4.52 | 78 |
| 2011 | 4.16 | 109 |
| 2010 | 5.01 | 65 |
| 2009 | -.68 | 164 |
| 2008 | 14.93 | 34 |
| 2007 | 5.39 | 86 |
| 2006 | 6.25 | 70 |
| 2005 | 3.49 | 101 |
| 2004 | 3.36 | 93 |
| 2003 | 1.63 | 124 |
| 2002 | 1.83 | 126 |
| 2001 | 1.77 | 136 |
| 2000 | 0.67 | 142 |
| 1999 | 0.61 | 132 |
| 1998 | 3.09 | 105 |
| 1997 | 3.04 | 110 |
| 1996 | 6.5 | 85 |
| 1995 | 2.35 | 134 |
| 1994 | 3.52 | 115 |
| 1993 | 3.32 | 108 |
| 1992 | 4 | 99 |
| 1991 | 8.16 | 78 |
| 1990 | 16.19 | 44 |
| 1989 | 25.71 | 24 |
| 1988 | 6.61 | 73 |
| 1987 | -.2 | 116 |
| 1986 | 0 | 116 |