| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.197 | 133 |
| 2015 | 0.417 | 141 |
| 2014 | 0.849 | 139 |
| 2013 | 1.519 | 128 |
| 2012 | 2.646 | 109 |
| 2011 | 2.615 | 108 |
| 2010 | 2.409 | 116 |
| 2009 | 2.481 | 123 |
| 2008 | 4.633 | 89 |
| 2007 | 3.878 | 111 |
| 2006 | 2.754 | 132 |
| 2005 | 2.067 | 135 |
| 2004 | 1.961 | 125 |
| 2003 | 2.082 | 127 |
| 2002 | 2.5 | 127 |
| 2001 | 3.083 | 124 |
| 2000 | 2.954 | 135 |
| 1999 | 1.848 | 142 |
| 1998 | 2.922 | 142 |
| 1997 | 3.958 | 126 |
| 1996 | 6.115 | 97 |
| 1995 | 7.678 | 79 |
| 1994 | 6.703 | 82 |
| 1993 | 9.628 | 51 |
| 1992 | 10.433 | 52 |
| 1991 | 10.472 | 52 |
| 1990 | 10.654 | 46 |
| 1989 | 9.546 | 51 |
| 1988 | 9.06 | 49 |
| 1987 | 8.965 | 44 |
| 1986 | 9.05 | 47 |