| 年度 | 实际值 |
|---|---|
| 1995 | 69.9 |
| 1996 | 67.1 |
| 1997 | 65.7 |
| 1998 | 63.2 |
| 1999 | 62.6 |
| 2000 | 58.9 |
| 2001 | 59.24 |
| 2002 | 60.13 |
| 2003 | 64.9 |
| 2004 | 69.29 |
| 2005 | 64.82 |
| 2006 | 64.19 |
| 2007 | 65.71 |
| 2008 | 67.96 |
| 2009 | |
| 2010 | 69.49 |
| 2011 | 68.09 |
| 2012 | 66.47 |
| 2013 | 64.52 |
| 2014 | 62.34 |
| 2015 | 56.66 |
| 2016 | 55.4 |
| 2017 | |
| 2018 | 53.59 |