| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.4 | 66 |
| 2015 | 3.5 | 71 |
| 2014 | 4.7 | 62 |
| 2013 | 3.47 | 83 |
| 2012 | -.55 | 125 |
| 2011 | 1.95 | 124 |
| 2010 | 8.31 | 47 |
| 2009 | 18.64 | 7 |
| 2008 | 8.38 | 34 |
| 2007 | 13.72 | 14 |
| 2006 | 9.94 | 42 |
| 2005 | 7.23 | 47 |
| 2004 | 5.01 | 83 |
| 2003 | 11.05 | 30 |
| 2002 | -7.31 | 154 |
| 2001 | -10.72 | 163 |
| 2000 | -.98 | 138 |
| 1999 | 3.27 | 81 |
| 1998 | 2.17 | 97 |
| 1997 | -.33 | 125 |
| 1996 | 8.24 | 27 |
| 1995 | 4.89 | 59 |
| 1994 | 2.41 | 88 |
| 1993 | -7.44 | 110 |
| 1992 | 2.43 | 60 |
| 1991 | 3.94 | 47 |
| 1990 | 9.33 | 21 |
| 1989 | 7.99 | 26 |
| 1988 | 5.73 | 45 |
| 1987 | 2.65 | 66 |
| 1986 | -1.78 | 92 |