| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2013 | 10.62 | 11 |
| 2012 | 10.03 | 22 |
| 2011 | 9.47 | 34 |
| 2010 | 10.78 | 14 |
| 2009 | 6.28 | 48 |
| 2008 | 8.58 | 96 |
| 2007 | 8.83 | 36 |
| 2006 | 10.9 | 24 |
| 2005 | 9.64 | 36 |
| 2004 | 4.42 | 74 |
| 2003 | 13.44 | 25 |
| 2002 | 25.87 | 8 |
| 2001 | -1.07 | 163 |
| 2000 | -.94 | 158 |
| 1999 | -1.17 | 150 |
| 1998 | 0.92 | 142 |
| 1997 | 0.53 | 156 |
| 1996 | 0.16 | 158 |
| 1995 | 3.38 | 121 |
| 1994 | 4.18 | 109 |
| 1993 | 10.61 | 64 |
| 1992 | 24.9 | 30 |
| 1991 | 171.67 | 8 |
| 1990 | 2313.96 | 4 |
| 1989 | 3079.81 | 3 |
| 1988 | 342.96 | 4 |
| 1987 | 131.33 | 6 |
| 1986 | 90.1 | 5 |