| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.6 | 39 |
| 2015 | 3.56 | 61 |
| 2014 | 3.23 | 75 |
| 2013 | 2.82 | 87 |
| 2012 | 3.65 | 96 |
| 2011 | 3.37 | 131 |
| 2010 | 1.53 | 138 |
| 2009 | 2.94 | 90 |
| 2008 | 5.79 | 125 |
| 2007 | 1.78 | 156 |
| 2006 | 2 | 153 |
| 2005 | 1.62 | 153 |
| 2004 | 3.66 | 87 |
| 2003 | 2.26 | 106 |
| 2002 | 0.19 | 152 |
| 2001 | 1.98 | 133 |
| 2000 | 3.76 | 81 |
| 1999 | 3.47 | 77 |
| 1998 | 7.25 | 64 |
| 1997 | 8.56 | 53 |
| 1996 | 11.54 | 55 |
| 1995 | 11.13 | 65 |
| 1994 | 23.74 | 54 |
| 1993 | 48.58 | 23 |
| 1992 | 73.53 | 12 |
| 1991 | 409.53 | 4 |
| 1990 | 7481.66 | 2 |
| 1989 | 3398.68 | 2 |
| 1988 | 667.02 | 2 |
| 1987 | 85.82 | 7 |
| 1986 | 77.92 | 8 |