| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 25164 | 9 |
| 2015 | 24971 | 12 |
| 2014 | 24687 | 13 |
| 2013 | 24576 | 13 |
| 2012 | 24462 | 12 |
| 2011 | 24184 | 13 |
| 2010 | 23423 | 15 |
| 2009 | 23301 | 13 |
| 2008 | 23207 | 17 |
| 2007 | 23025 | 17 |
| 2006 | 22995 | 17 |
| 2005 | 22630 | 16 |
| 2004 | 22524 | 14 |
| 2003 | 22350 | 13 |
| 2002 | 22336 | 13 |
| 2001 | 22548 | 12 |
| 2000 | 22228 | 12 |
| 1999 | 21796 | 9 |
| 1998 | 21266 | 9 |
| 1997 | 21005 | 8 |
| 1996 | 20872 | 8 |
| 1995 | 20689 | 7 |
| 1994 | 20348 | 7 |
| 1993 | 20020 | 7 |
| 1992 | 20023 | 8 |
| 1991 | 19542 | 8 |
| 1990 | 18862 | 9 |
| 1989 | 18255 | 11 |
| 1988 | 17854 | 11 |
| 1987 | 17460 | 11 |
| 1986 | 16885 | 11 |