| 年度 | 实际值 |
|---|---|
| 1995 | 55.4 |
| 1996 | 56.6 |
| 1997 | 49.43 |
| 1998 | 54.6 |
| 1999 | 55.3 |
| 2000 | 55.3 |
| 2001 | 56.26 |
| 2002 | 56.41 |
| 2003 | 57.71 |
| 2004 | 60.55 |
| 2005 | 54.64 |
| 2006 | 56.12 |
| 2007 | 59.13 |
| 2008 | 66.43 |
| 2009 | |
| 2010 | 53.07 |
| 2011 | 54.72 |
| 2012 | 53.24 |
| 2013 | 54.29 |
| 2014 | 54.28 |
| 2015 | 51.5 |
| 2016 | 51.42 |
| 2017 | 54.36 |
| 2018 | 55.66 |