| 年度 | 实际值 |
|---|---|
| 1992 | 13.6 |
| 1993 | 15.3 |
| 1994 | |
| 1995 | 11.43 |
| 1996 | 12.61 |
| 1997 | 10.63 |
| 1998 | 3.32 |
| 1999 | 9.37 |
| 2000 | 20 |
| 2001 | 8.94 |
| 2002 | 8.09 |
| 2003 | -1.58 |
| 2004 | 9.09 |
| 2005 | 9.82 |
| 2006 | 7.01 |
| 2007 | 8.33 |
| 2008 | 8.54 |
| 2009 | |
| 2010 | 13.74 |
| 2011 | 10.5 |
| 2012 | 11.1 |
| 2013 | 10.4 |
| 2014 | 10.7 |
| 2015 | 10.7 |
| 2016 | 10.7 |
| 2017 | 11.2 |
| 2018 | 10.23 |