| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.038 | 138 |
| 2015 | 0.039 | 152 |
| 2014 | 0.05 | 156 |
| 2013 | 0.045 | 157 |
| 2012 | 0.063 | 158 |
| 2011 | 0.053 | 157 |
| 2010 | 0.018 | 162 |
| 2009 | 0.029 | 163 |
| 2008 | 1.099 | 157 |
| 2007 | 2.851 | 142 |
| 2006 | 2.847 | 128 |
| 2005 | 1.579 | 152 |
| 2004 | 0.08 | 158 |
| 2003 | 0.323 | 152 |
| 2002 | 0.631 | 147 |
| 2001 | 2.587 | 134 |
| 2000 | 5.334 | 92 |
| 1999 | 5.299 | 95 |
| 1998 | 7.003 | 88 |
| 1997 | 6.22 | 91 |
| 1996 | 5.23 | 108 |
| 1995 | 5.934 | 95 |
| 1994 | 4.208 | 109 |
| 1993 | 2.75 | 120 |
| 1992 | 3.5 | 112 |
| 1991 | 5.875 | 91 |
| 1990 | 7.125 | 77 |
| 1989 | 7.042 | 75 |
| 1988 | 4.563 | 91 |
| 1987 | 3.5 | 100 |
| 1986 | 3.5 | 105 |