| 年度 | 实际值 |
|---|---|
| 1995 | 77.6 |
| 1996 | 77.2 |
| 1997 | 77.51 |
| 1998 | 76 |
| 1999 | 76.4 |
| 2000 | 81.6 |
| 2001 | 80.75 |
| 2002 | 77.25 |
| 2003 | 79.47 |
| 2004 | 80.75 |
| 2005 | 82.28 |
| 2006 | 80.68 |
| 2007 | 76.24 |
| 2008 | 76.53 |
| 2009 | |
| 2010 | 72.55 |
| 2011 | 71.55 |
| 2012 | 70.85 |
| 2013 | 69.49 |
| 2014 | 66.6 |
| 2015 | 64.64 |
| 2016 | 62.17 |
| 2017 | |
| 2018 | 62.21 |