| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.5 | 96 |
| 2015 | 1.5 | 110 |
| 2014 | 2.75 | 82 |
| 2013 | 3 | 89 |
| 2012 | 3 | 100 |
| 2011 | 3.5 | 83 |
| 2010 | 2.75 | 110 |
| 2009 | 2.25 | 127 |
| 2008 | 2.25 | 145 |
| 2007 | 4.14 | 103 |
| 2006 | 2.52 | 139 |
| 2005 | 2.25 | 127 |
| 2004 | 2.25 | 121 |
| 2003 | 1.98 | 132 |
| 2002 | 1.98 | 133 |
| 2001 | 2.25 | 138 |
| 2000 | 2.25 | 139 |
| 1999 | 2.25 | 140 |
| 1998 | 3.78 | 129 |
| 1997 | 5.67 | 97 |
| 1996 | 7.47 | 80 |
| 1995 | 10.98 | 58 |
| 1994 | 10.98 | 49 |
| 1993 | 10.98 | 50 |
| 1992 | 7.56 | 67 |
| 1991 | 7.56 | 69 |
| 1990 | 8.64 | 60 |
| 1989 | 11.34 | 44 |
| 1988 | 8.64 | 51 |
| 1987 | 7.2 | 58 |
| 1986 | 7.2 | 66 |