| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.75 | 122 |
| 2015 | 1.4 | 105 |
| 2014 | 1.04 | 126 |
| 2013 | 3.13 | 62 |
| 2012 | 4.37 | 40 |
| 2011 | 5.12 | 41 |
| 2010 | 4.82 | 51 |
| 2009 | -2.54 | 118 |
| 2008 | 2.47 | 94 |
| 2007 | 3.81 | 106 |
| 2006 | 5.19 | 73 |
| 2005 | 4.61 | 64 |
| 2004 | 6.04 | 51 |
| 2003 | 2.93 | 89 |
| 2002 | 1.93 | 87 |
| 2001 | 2.08 | 84 |
| 2000 | 4.04 | 66 |
| 1999 | -1.66 | 158 |
| 1998 | 2.97 | 85 |
| 1997 | 5.99 | 32 |
| 1996 | 5.32 | 41 |
| 1995 | 7.37 | 17 |
| 1994 | 3.47 | 61 |
| 1993 | 4.96 | 26 |
| 1992 | 9.43 | 12 |
| 1991 | 6.08 | 19 |
| 1990 | 1.65 | 76 |
| 1989 | 8.09 | 12 |
| 1988 | 5.54 | 40 |
| 1987 | 4.68 | 38 |
| 1986 | 3.65 | 41 |