| 年度 | 实际值 |
|---|---|
| 1992 | 7.7 |
| 1993 | 7.9 |
| 1994 | |
| 1995 | 7.32 |
| 1996 | 6.89 |
| 1997 | 6.19 |
| 1998 | 6.84 |
| 1999 | 6.51 |
| 2000 | 10.22 |
| 2001 | 4 |
| 2002 | 4.04 |
| 2003 | 4.53 |
| 2004 | 5.21 |
| 2005 | .08 |
| 2006 | 7.35 |
| 2007 | 9.28 |
| 2008 | 7.7 |
| 2009 | |
| 2010 | 3.48 |
| 2011 | 7.1 |
| 2012 | 4.8 |
| 2013 | 8 |
| 2014 | 6.7 |
| 2015 | 2.84 |
| 2016 | 6.75 |
| 2017 | -0.88 |
| 2018 | 6.86 |