| 年度 | 实际值 |
|---|---|
| 1995 | 60.8 |
| 1996 | 57.4 |
| 1997 | 55.15 |
| 1998 | 54.6 |
| 1999 | 55.6 |
| 2000 | 55.6 |
| 2001 | 55.79 |
| 2002 | 56.19 |
| 2003 | 57.97 |
| 2004 | 63.49 |
| 2005 | 61.67 |
| 2006 | 66.96 |
| 2007 | 67.74 |
| 2008 | 67.11 |
| 2009 | |
| 2010 | 72.74 |
| 2011 | 74.73 |
| 2012 | 73.44 |
| 2013 | 72.14 |
| 2014 | 71.26 |
| 2015 | 61.75 |
| 2016 | 59.5 |
| 2017 | |
| 2018 | 58.25 |