| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2008 | 8 | 112 |
| 2007 | 7.5 | 126 |
| 2006 | 7 | 132 |
| 2005 | 7 | 123 |
| 2004 | 7 | 123 |
| 2003 | 7 | 118 |
| 2002 | 8.661 | 107 |
| 2001 | 10.865 | 99 |
| 2000 | 10.892 | 104 |
| 1999 | 10.582 | 110 |
| 1998 | 10.5 | 112 |
| 1997 | 10.5 | 108 |
| 1996 | 13.917 | 84 |
| 1995 | 15.083 | 78 |
| 1994 | 14.333 | 72 |
| 1993 | 14 | 73 |
| 1992 | 8 | 103 |
| 1991 | 6 | 107 |
| 1990 | 6 | 104 |
| 1989 | 6 | 104 |
| 1988 | 6 | 102 |
| 1987 | 6 | 102 |
| 1986 | 7.25 | 97 |