| 年度 | 实际值 |
|---|---|
| 1992 | 6.3 |
| 1993 | 7.5 |
| 1994 | |
| 1995 | 6.47 |
| 1996 | 5.6 |
| 1997 | 5.5 |
| 1998 | 5.6 |
| 1999 | 6.22 |
| 2000 | 10.8 |
| 2001 | 5.04 |
| 2002 | 6 |
| 2003 | 5.53 |
| 2004 | 5.04 |
| 2005 | 7.27 |
| 2006 | 8.16 |
| 2007 | 9.03 |
| 2008 | 8.35 |
| 2009 | |
| 2010 | 10.69 |
| 2011 | 9 |
| 2012 | 9.8 |
| 2013 | 10.9 |
| 2014 | 11.3 |
| 2015 | 11.78 |
| 2016 | 10.05 |
| 2017 | -0.37 |
| 2018 | 8.87 |