| 年度 | 实际值 |
|---|---|
| 1992 | 75.4 |
| 1993 | |
| 1994 | |
| 1995 | 68.8 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 68.1 |
| 2000 | 68.1 |
| 2001 | 67.9 |
| 2002 | 67.5 |
| 2003 | 67 |
| 2004 | 66.8 |
| 2005 | 66.5 |
| 2006 | 66.4 |
| 2007 | 66.47 |
| 2008 | 66.7 |
| 2009 | 66.8 |
| 2010 | 67 |
| 2011 | 67.1 |
| 2012 | 67 |
| 2013 | 66.9 |
| 2014 | 66.9 |
| 2015 | 66.8 |
| 2016 | 66.7146 |
| 2017 | 66.2 |
| 2018 | 65.9395 |