| 年度 | 实际值 |
|---|---|
| 1995 | 78.4 |
| 1996 | 75.4 |
| 1997 | 57.28 |
| 1998 | 70 |
| 1999 | 69.2 |
| 2000 | 65.2 |
| 2001 | 65.8 |
| 2002 | 67.16 |
| 2003 | 71.32 |
| 2004 | 76 |
| 2005 | 69.39 |
| 2006 | 67.79 |
| 2007 | 69.44 |
| 2008 | 72.61 |
| 2009 | |
| 2010 | 68.25 |
| 2011 | 71.61 |
| 2012 | 68.53 |
| 2013 | 65.72 |
| 2014 | 62.33 |
| 2015 | 55.53 |
| 2016 | 53.37 |
| 2017 | 53.91 |
| 2018 | 52.48 |