| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2014 | 2 | 107 |
| 2013 | 4.1 | 68 |
| 2012 | 4.1 | 61 |
| 2011 | 4.1 | 84 |
| 2010 | -.71 | 116 |
| 2009 | -3.14 | 135 |
| 2008 | 8.32 | 35 |
| 2007 | 2.3 | 98 |
| 2006 | 2.61 | 91 |
| 2005 | 3 | 69 |
| 2004 | 2.7 | 100 |
| 2003 | 2.91 | 80 |
| 2002 | 2.71 | 82 |
| 2001 | 5.3 | 51 |
| 2000 | 9.58 | 17 |
| 1999 | 4.4 | 66 |
| 1998 | 0.1 | 102 |
| 1997 | 7.9 | 18 |
| 1996 | -.2 | 118 |
| 1995 | 9.6 | 19 |
| 1994 | -4.72 | 108 |
| 1993 | 2.14 | 60 |
| 1992 | 0 | 80 |
| 1991 | 0.4 | 79 |
| 1990 | 5.4 | 42 |
| 1989 | 2.77 | 64 |
| 1988 | 4.27 | 47 |
| 1987 | 3.3 | 45 |
| 1986 | 3.27 | 50 |