| 年度 | 实际值 |
|---|---|
| 1989 | 8868 |
| 1990 | 8479 |
| 1991 | 6559 |
| 1992 | 5963 |
| 1993 | 2230 |
| 1994 | 1161 |
| 1995 | 971 |
| 1996 | 1142 |
| 1997 | 2462 |
| 1998 | 2583 |
| 1999 | 639 |
| 2000 | 232 |
| 2001 | 9238 |
| 2002 | 12210 |
| 2003 | 13485 |
| 2004 | 13718 |
| 2005 | 12632 |
| 2006 | 8919 |
| 2007 | 7413 |
| 2008 | 5205 |
| 2009 | 4149 |
| 2010 | 5005 |
| 2011 | 4132 |
| 2012 | 2779 |
| 2013 | 3065 |
| 2014 | 2945 |
| 2015 | 2923 |