| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | -.01 | 131 |
| 2015 | -.41 | 151 |
| 2014 | -.74 | 161 |
| 2013 | -.87 | 169 |
| 2012 | -.72 | 159 |
| 2011 | -.37 | 151 |
| 2010 | 0.06 | 128 |
| 2009 | 0.43 | 108 |
| 2008 | 0.72 | 97 |
| 2007 | 0.88 | 87 |
| 2006 | 0.94 | 90 |
| 2005 | 0.99 | 84 |
| 2004 | 1.06 | 83 |
| 2003 | 1.11 | 77 |
| 2002 | 1.15 | 76 |
| 2001 | 1.17 | 78 |
| 2000 | 1.17 | 77 |
| 1999 | 1.17 | 77 |
| 1998 | 1.22 | 75 |
| 1997 | 1.34 | 73 |
| 1996 | 1.52 | 72 |
| 1995 | 1.69 | 59 |
| 1994 | 1.85 | 54 |
| 1993 | 1.99 | 52 |
| 1992 | 2.09 | 50 |
| 1991 | 2.17 | 49 |
| 1990 | 2.24 | 40 |
| 1989 | 2.31 | 39 |
| 1988 | 2.44 | 38 |
| 1987 | 2.62 | 33 |
| 1986 | 2.85 | 26 |