| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | -.2 | 104 |
| 2015 | -.5 | 148 |
| 2014 | -.15 | 154 |
| 2013 | 1.41 | 134 |
| 2012 | 2.45 | 134 |
| 2011 | 3.2 | 140 |
| 2010 | 1.8 | 132 |
| 2009 | -.29 | 157 |
| 2008 | 4.08 | 151 |
| 2007 | 2.79 | 129 |
| 2006 | 3.52 | 107 |
| 2005 | 3.37 | 107 |
| 2004 | 3.04 | 99 |
| 2003 | 3.04 | 90 |
| 2002 | 3.07 | 87 |
| 2001 | 3.59 | 95 |
| 2000 | 3.43 | 85 |
| 1999 | 2.31 | 98 |
| 1998 | 1.83 | 123 |
| 1997 | 1.97 | 131 |
| 1996 | 3.56 | 112 |
| 1995 | 4.67 | 113 |
| 1994 | 4.72 | 107 |
| 1993 | 4.57 | 95 |
| 1992 | 5.93 | 80 |
| 1991 | 5.94 | 91 |
| 1990 | 6.72 | 82 |
| 1989 | 6.79 | 70 |
| 1988 | 4.84 | 82 |
| 1987 | 5.25 | 70 |
| 1986 | 8.8 | 53 |