| 年度 | 实际值 |
|---|---|
| 1992 | 6.4 |
| 1993 | 5.3 |
| 1994 | |
| 1995 | 10.15 |
| 1996 | 9.08 |
| 1997 | |
| 1998 | |
| 1999 | 8.21 |
| 2000 | 13.33 |
| 2001 | 8.57 |
| 2002 | 6.07 |
| 2003 | 9.1 |
| 2004 | 12.62 |
| 2005 | 10.94 |
| 2006 | 13.21 |
| 2007 | 14.65 |
| 2008 | 13.89 |
| 2009 | |
| 2010 | 11.11 |
| 2011 | 11.3 |
| 2012 | 9.2 |
| 2013 | 6.2 |
| 2014 | 30.3 |
| 2015 | 11.29 |
| 2016 | 12.07 |
| 2017 | 6 |
| 2018 | 10.3 |