| 年度 | 实际值 |
|---|---|
| 1992 | 8.12 |
| 1993 | 8.25 |
| 1994 | 8.4 |
| 1995 | 8.51 |
| 1996 | 8.62 |
| 1997 | |
| 1998 | |
| 1999 | 9.1293 |
| 2000 | 9.2227 |
| 2001 | 9.391 |
| 2002 | 9.1424 |
| 2003 | 9.2537 |
| 2004 | 9.459 |
| 2005 | 9.6694 |
| 2006 | 10.0238 |
| 2007 | 10.2894 |
| 2008 | 10.5206 |
| 2009 | 11 |
| 2010 | 11 |
| 2011 | 11 |
| 2012 | 11 |
| 2013 | 12 |
| 2014 | 12 |
| 2015 | 12 |
| 2016 | 12 |
| 2017 | 12 |