| 年度 | 实际值 |
|---|---|
| 1995 | 59.9 |
| 1996 | 57 |
| 1997 | 55.68 |
| 1998 | 57.7 |
| 1999 | 58.9 |
| 2000 | 60.5 |
| 2001 | 57.88 |
| 2002 | 58.78 |
| 2003 | 63.79 |
| 2004 | 66.29 |
| 2005 | 62.41 |
| 2006 | 61.42 |
| 2007 | 59.24 |
| 2008 | 56.53 |
| 2009 | |
| 2010 | 54.43 |
| 2011 | 53.88 |
| 2012 | 53.26 |
| 2013 | 51.66 |
| 2014 | 50.24 |
| 2015 | 47.63 |
| 2016 | 46.02 |
| 2017 | 47.3 |
| 2018 | 47.28 |