| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.49 | 93 |
| 2015 | 3.83 | 55 |
| 2014 | 4.44 | 51 |
| 2013 | 6.69 | 38 |
| 2012 | 0.78 | 117 |
| 2011 | 7.94 | 33 |
| 2010 | 0.74 | 94 |
| 2009 | 1.72 | 95 |
| 2008 | 1.67 | 114 |
| 2007 | 3.42 | 78 |
| 2006 | 4.31 | 64 |
| 2005 | 7.06 | 35 |
| 2004 | 2.39 | 104 |
| 2003 | 6.61 | 40 |
| 2002 | 1.77 | 94 |
| 2001 | 4.97 | 53 |
| 2000 | 0.83 | 98 |
| 1999 | 8.85 | 25 |
| 1998 | -2.98 | 129 |
| 1997 | 5.22 | 36 |
| 1996 | 5.93 | 41 |
| 1995 | 3.35 | 66 |
| 1994 | 5.29 | 35 |
| 1993 | -.5 | 85 |
| 1992 | 4.02 | 50 |
| 1991 | 8.53 | 17 |
| 1990 | 4.43 | 48 |
| 1989 | 6.86 | 23 |
| 1988 | 5.63 | 38 |
| 1987 | 5.44 | 30 |
| 1986 | 12.8 | 11 |