| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2008 | 23.39 | 38 |
| 2007 | 22.21 | 58 |
| 2006 | 19.99 | 73 |
| 2005 | 18.59 | 59 |
| 2004 | 19.26 | 56 |
| 2003 | 12.44 | 87 |
| 2002 | 15.93 | 59 |
| 2001 | 9.68 | 105 |
| 2000 | 13.07 | 79 |
| 1999 | 13.71 | 77 |
| 1998 | -1.09 | 142 |
| 1997 | 19.83 | 61 |
| 1996 | 9.05 | 106 |
| 1995 | 9.03 | 106 |
| 1994 | 23.17 | 68 |
| 1993 | 8.78 | 90 |
| 1992 | 15.22 | 71 |
| 1991 | 15.93 | 68 |
| 1990 | 19.87 | 49 |
| 1989 | 15.57 | 67 |
| 1988 | 11.08 | 82 |
| 1987 | 5.63 | 96 |
| 1986 | 11.39 | 72 |