| 年度 | 实际值 |
|---|---|
| 1993 | 8000 |
| 1994 | 8300 |
| 1995 | 7700 |
| 1996 | 10000 |
| 1997 | 10200 |
| 1998 | 11400 |
| 1999 | |
| 2000 | 12874 |
| 2001 | 14246 |
| 2002 | 14840 |
| 2003 | 17890 |
| 2004 | 19900 |
| 2005 | 19100 |
| 2006 | 20874 |
| 2007 | 21047 |
| 2008 | 20751 |
| 2009 | 19827 |
| 2010 | 19446 |
| 2011 | 19446 |
| 2012 | 19261 |
| 2013 | 18646 |
| 2014 | 17985 |
| 2015 | 18207 |
| 2016 | 18454 |
| 2017 | 18468 |