| 年度 | 实际值 |
|---|---|
| 1995 | 56.1 |
| 1996 | 59.4 |
| 1997 | 30.92 |
| 1998 | 52.1 |
| 1999 | 48.9 |
| 2000 | 55.2 |
| 2001 | 56.87 |
| 2002 | 58.54 |
| 2003 | 62.07 |
| 2004 | 62.92 |
| 2005 | 57.55 |
| 2006 | 54.83 |
| 2007 | 57.51 |
| 2008 | 57.26 |
| 2009 | |
| 2010 | 58.01 |
| 2011 | 62.92 |
| 2012 | 62.53 |
| 2013 | 58.76 |
| 2014 | 58.57 |
| 2015 | 57.97 |
| 2016 | 55.21 |
| 2017 | 52.94 |
| 2018 | 47.75 |