| 年度 | 实际值 |
|---|---|
| 1992 | 88.1 |
| 1993 | |
| 1994 | |
| 1995 | 87.6 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 87.6 |
| 2000 | 87.2 |
| 2001 | 86.9 |
| 2002 | 86.5 |
| 2003 | 85.9 |
| 2004 | 85.9 |
| 2005 | 85.8 |
| 2006 | 86 |
| 2007 | 86.02 |
| 2008 | 85.9 |
| 2009 | 85.9 |
| 2010 | 85.9 |
| 2011 | 85.8 |
| 2012 | 85.6 |
| 2013 | 85.4 |
| 2014 | 85.35 |
| 2015 | 85.12 |
| 2016 | 85.0321 |
| 2017 | 84.8 |
| 2018 | 84.3617 |