| 年度 | 实际值 |
|---|---|
| 1992 | 64.85 |
| 1993 | 65.55 |
| 1994 | 78.11 |
| 1995 | 78.64 |
| 1996 | 79.22 |
| 1997 | 79.98 |
| 1998 | 80.93 |
| 1999 | 81.66 |
| 2000 | 82.3 |
| 2001 | 82.53 |
| 2002 | 82.39 |
| 2003 | 81.97 |
| 2004 | 81.81 |
| 2005 | 81.93 |
| 2006 | 82.09 |
| 2007 | 82.51 |
| 2008 | 82.4 |
| 2009 | |
| 2010 | 81.49 |
| 2011 | 81.6 |
| 2012 | 80.8 |
| 2013 | 79.1 |
| 2014 | 79 |
| 2015 | 77.6 |
| 2016 | 78 |
| 2017 | 77 |
| 2018 | 76 |