| 时间 | 值 | 世界排名 |
|---|---|---|
| 2008 | 6723052073.3381 | 1 |
| 2007 | 9686.7717 | 3 |
| 2006 | 164.5474 | 46 |
| 2005 | 22.389 | 81 |
| 2004 | 5.0744 | 110 |
| 2003 | 0.6982 | 163 |
| 2002 | 0.0551 | 170 |
| 2001 | 0.0551 | 171 |
| 2000 | 0.0445 | 173 |
| 1999 | 0.0383 | 173 |
| 1998 | 0.0237 | 183 |
| 1997 | 0.0121 | 183 |
| 1996 | 0.01 | 181 |
| 1995 | 0.0087 | 179 |
| 1994 | 0.0082 | 176 |
| 1993 | 0.0065 | 170 |
| 1992 | 0.0051 | 162 |
| 1991 | 0.0036 | 157 |
| 1990 | 0.0025 | 153 |
| 1989 | 0.0021 | 152 |
| 1988 | 0.0018 | 148 |
| 1987 | 0.0017 | 149 |
| 1986 | 0.0017 | 149 |