| 年度 | 实际值 |
|---|---|
| 1992 | 8.4 |
| 1993 | |
| 1994 | |
| 1995 | 8.4 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 11.2878 |
| 2000 | 11.9388 |
| 2001 | 9.075 |
| 2002 | 9.0581 |
| 2003 | 8.9874 |
| 2004 | 8.7148 |
| 2005 | 8.6381 |
| 2006 | 10.2143 |
| 2007 | 10.6932 |
| 2008 | 10.2931 |
| 2009 | 10.2835 |
| 2010 | 10.2011 |
| 2011 | 10.6007 |
| 2012 | 10.882 |
| 2013 | 10.1439 |
| 2014 | 10.2423 |
| 2015 | 10.2608 |