| 年度 | 实际值 |
|---|---|
| 1978 | 7800 |
| 1979 | 8600 |
| 1980 | 8300 |
| 1981 | 10400 |
| 1982 | 13100 |
| 1983 | 11600 |
| 1984 | 11400 |
| 1985 | 12200 |
| 1986 | 13000 |
| 1987 | 10700 |
| 1988 | 10800 |
| 1989 | 10700 |
| 1990 | 11800 |
| 1991 | 11800 |
| 1992 | 11600 |
| 1993 | 9800 |
| 1994 | 9100 |
| 1995 | 8100 |
| 1996 | 8200 |
| 1997 | 8700 |
| 1998 | 9200 |
| 1999 | 8300 |
| 2000 | 7900 |
| 2001 | 6700 |
| 2002 | 6700 |
| 2003 | 7100 |
| 2004 | 5600 |
| 2005 | 4900 |
| 2006 | 3100 |
| 2007 | 2300 |
| 2008 | 2700 |
| 2009 | 3600 |
| 2010 | 3700 |
| 2011 | 3800 |
| 2012 | 3600 |
| 2013 | 3900 |
| 2014 | 2000 |
| 2015 | 8100 |