| 年度 | 实际值 |
|---|---|
| 1995 | 56.6 |
| 1996 | 56.8 |
| 1997 | 55.28 |
| 1998 | 50.4 |
| 1999 | 48.9 |
| 2000 | 46.6 |
| 2001 | 47.34 |
| 2002 | 48.65 |
| 2003 | 51.1 |
| 2004 | 52.16 |
| 2005 | 53.18 |
| 2006 | 54.34 |
| 2007 | 55.02 |
| 2008 | 61.1 |
| 2009 | |
| 2010 | 64.42 |
| 2011 | 65.03 |
| 2012 | 64.09 |
| 2013 | 62.06 |
| 2014 | 57.42 |
| 2015 | 48.09 |
| 2016 | 47.17 |
| 2017 | |
| 2018 | 46.57 |