| 年度 | 实际值 |
|---|---|
| 1992 | 83.2 |
| 1993 | |
| 1994 | |
| 1995 | 83.2 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 83.2 |
| 2000 | 83.4 |
| 2001 | 83 |
| 2002 | 83.2 |
| 2003 | 83 |
| 2004 | 83 |
| 2005 | 83 |
| 2006 | 83 |
| 2007 | 82.72 |
| 2008 | 82.4 |
| 2009 | 82.0104 |
| 2010 | 82.0766 |
| 2011 | 82.0624 |
| 2012 | 81.7398 |
| 2013 | 81.82 |
| 2014 | 81.81 |
| 2015 | 81.58 |
| 2016 | 81.5 |
| 2017 | 81.2 |
| 2018 | 80.82 |