| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.77 | 77 |
| 2015 | 1.15 | 90 |
| 2014 | 0.45 | 108 |
| 2013 | 0.47 | 109 |
| 2012 | 1.15 | 93 |
| 2011 | 3.25 | 60 |
| 2010 | 0.53 | 116 |
| 2009 | 0.4 | 62 |
| 2008 | 0.79 | 95 |
| 2007 | 0.13 | 129 |
| 2006 | 1.61 | 102 |
| 2005 | 0.47 | 124 |
| 2004 | 0.78 | 118 |
| 2003 | 0.06 | 111 |
| 2002 | -.94 | 113 |
| 2001 | 1.44 | 76 |
| 2000 | 1.98 | 73 |
| 1999 | 2.49 | 61 |
| 1998 | 1.24 | 91 |
| 1997 | 0.64 | 96 |
| 1996 | 0.89 | 95 |
| 1995 | 1.68 | 62 |
| 1994 | 1.64 | 56 |
| 1993 | -.02 | 71 |
| 1992 | 2.46 | 32 |
| 1991 | 3.6 | 32 |
| 1990 | 3.33 | 28 |
| 1989 | 2.24 | 46 |
| 1988 | 2.26 | 49 |
| 1987 | 3.4 | 30 |
| 1986 | 3.77 | 28 |