| 年度 | 实际值 |
|---|---|
| 1992 | 11.2 |
| 1993 | 10.9 |
| 1994 | |
| 1995 | 10.76 |
| 1996 | 10.04 |
| 1997 | 9.9 |
| 1998 | 7.36 |
| 1999 | 8.62 |
| 2000 | 10.62 |
| 2001 | 4.01 |
| 2002 | 4.13 |
| 2003 | 3.78 |
| 2004 | 3.7 |
| 2005 | .7 |
| 2006 | 4.5 |
| 2007 | 4.02 |
| 2008 | 1.49 |
| 2009 | |
| 2010 | -1.81 |
| 2011 | 3.3 |
| 2012 | 2.3 |
| 2013 | 3.6 |
| 2014 | 1.9 |
| 2015 | 2.8 |
| 2016 | 3.56 |
| 2017 | 0.23 |
| 2018 | 5.94 |