| 年度 | 实际值 |
|---|---|
| 1992 | 6.7 |
| 1993 | 5.3 |
| 1994 | |
| 1995 | 2.43 |
| 1996 | 2.69 |
| 1997 | 2.8 |
| 1998 | 5.84 |
| 1999 | 2.7 |
| 2000 | 3.74 |
| 2001 | 3.69 |
| 2002 | 2.78 |
| 2003 | 2.93 |
| 2004 | 3 |
| 2005 | 3.26 |
| 2006 | 3.38 |
| 2007 | 3.85 |
| 2008 | 2.8 |
| 2009 | |
| 2010 | -.74 |
| 2011 | 4.6 |
| 2012 | 6.4 |
| 2013 | 6 |
| 2014 | 8.2 |
| 2015 | 8.84 |
| 2016 | 6.84 |
| 2017 | -8.18 |
| 2018 | 1.72 |