| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 2.204 | 113 |
| 2014 | 5.621 | 48 |
| 2013 | 7.894 | 24 |
| 2012 | 11.714 | 9 |
| 2011 | 5.987 | 57 |
| 2010 | 15.387 | 5 |
| 2009 | 9.026 | 14 |
| 2008 | 11.675 | 16 |
| 2007 | 11.114 | 31 |
| 2006 | 9.866 | 31 |
| 2005 | 8.834 | 33 |
| 2004 | 6.704 | 65 |
| 2003 | 7.033 | 38 |
| 2002 | 6.061 | 42 |
| 2001 | 7.021 | 25 |
| 2000 | 5.276 | 63 |
| 1999 | 7.7 | 19 |
| 1998 | 4.59 | 58 |
| 1997 | 4.933 | 72 |
| 1996 | 16.908 | 5 |
| 1995 | -2.191 | 117 |
| 1994 | -10.652 | 128 |
| 1993 | 7.25 | 24 |
| 1992 | -4.492 | 115 |
| 1991 | 5.544 | 34 |
| 1990 | -7.24 | 106 |
| 1989 | -8.897 | 106 |
| 1988 | 12.736 | 7 |
| 1987 | 7.321 | 25 |
| 1986 | -3.418 | 100 |