| 年度 | 实际值 |
|---|---|
| 1992 | 3.3 |
| 1993 | 3 |
| 1994 | |
| 1995 | 2.98 |
| 1996 | 6 |
| 1997 | 6.39 |
| 1998 | 4.89 |
| 1999 | 2.68 |
| 2000 | 3.66 |
| 2001 | 3.72 |
| 2002 | 4.19 |
| 2003 | 3.38 |
| 2004 | 3.24 |
| 2005 | 1.79 |
| 2006 | 2.79 |
| 2007 | 5.17 |
| 2008 | 5.09 |
| 2009 | |
| 2010 | 3.21 |
| 2011 | 2.7 |
| 2012 | -.5 |
| 2013 | 2.9 |
| 2014 | .5 |
| 2015 | -.17 |
| 2016 | 2.26 |
| 2017 | -8.76 |
| 2018 | 0.42 |