| 年度 | 实际值 |
|---|---|
| 1995 | 60.3 |
| 1996 | 57.8 |
| 1997 | 44.55 |
| 1998 | 55.1 |
| 1999 | 55.4 |
| 2000 | 52.6 |
| 2001 | 51.42 |
| 2002 | 51.6 |
| 2003 | 52.18 |
| 2004 | 63.98 |
| 2005 | 64.15 |
| 2006 | 63.74 |
| 2007 | 63.75 |
| 2008 | 63.66 |
| 2009 | |
| 2010 | 59.2 |
| 2011 | 63.44 |
| 2012 | 63.32 |
| 2013 | 61.61 |
| 2014 | 61.29 |
| 2015 | 58.65 |
| 2016 | 56.64 |
| 2017 | 52.31 |
| 2018 | 51.77 |