| 年度 | 实际值 |
|---|---|
| 1995 | 65.2 |
| 1996 | 64.1 |
| 1997 | 87.83 |
| 1998 | 60.1 |
| 1999 | 60.9 |
| 2000 | 63.5 |
| 2001 | 63.2 |
| 2002 | 62.97 |
| 2003 | 62.19 |
| 2004 | 66.27 |
| 2005 | 68.1 |
| 2006 | 66.48 |
| 2007 | 65.51 |
| 2008 | 64.43 |
| 2009 | |
| 2010 | 62.35 |
| 2011 | 61.21 |
| 2012 | 58.88 |
| 2013 | 57.1 |
| 2014 | 55.84 |
| 2015 | 53.75 |
| 2016 | 52.26 |
| 2017 | 51.99 |
| 2018 | 52.1 |