| 年度 | 实际值 |
|---|---|
| 1995 | 55.9 |
| 1996 | 60.1 |
| 1997 | 57.99 |
| 1998 | 65.1 |
| 1999 | 60 |
| 2000 | 58.9 |
| 2001 | 60.87 |
| 2002 | 61.89 |
| 2003 | 61.8 |
| 2004 | 68.34 |
| 2005 | 69.7 |
| 2006 | 70.77 |
| 2007 | 69.61 |
| 2008 | 70.3 |
| 2009 | |
| 2010 | 66.89 |
| 2011 | 64.13 |
| 2012 | 63.15 |
| 2013 | 58.77 |
| 2014 | 56.65 |
| 2015 | 44.38 |
| 2016 | 42.47 |
| 2017 | 37.42 |
| 2018 | 36.43 |