| 时间 | 值 | 世界排名 |
|---|---|---|
| 2009 | 0.3 | 126 |
| 2008 | 0.4 | 126 |
| 2007 | 0.4 | 124 |
| 2006 | 0.4 | 124 |
| 2005 | 0.3 | 124 |
| 2004 | 0.5 | 131 |
| 2003 | 0.3 | 133 |
| 2002 | 0.3 | 131 |
| 2001 | 0.2 | 146 |
| 2000 | 0.2 | 147 |
| 1999 | 0.2 | 146 |
| 1998 | 0.2 | 147 |
| 1997 | 0.1 | 148 |
| 1996 | 2.6 | 122 |
| 1995 | 8.5 | 107 |
| 1994 | 6.6 | 113 |
| 1993 | 4.6 | 112 |
| 1992 | 3.5 | 115 |
| 1991 | 2.5 | 116 |
| 1990 | 2.5 | 119 |