| 年度 | 实际值 |
|---|---|
| 1995 | 72.3 |
| 1996 | 69.9 |
| 1997 | 52.48 |
| 1998 | 64.1 |
| 1999 | 61.7 |
| 2000 | 61 |
| 2001 | 59.68 |
| 2002 | 60.8 |
| 2003 | 62.84 |
| 2004 | 66.14 |
| 2005 | 72.08 |
| 2006 | 73.72 |
| 2007 | 73.41 |
| 2008 | 76.37 |
| 2009 | |
| 2010 | 74.31 |
| 2011 | 74.78 |
| 2012 | 65.72 |
| 2013 | 62.27 |
| 2014 | 57.12 |
| 2015 | 54.85 |
| 2016 | 52.26 |
| 2017 | 51.9 |
| 2018 | 52.1 |