| 年度 | 实际值 |
|---|---|
| 1995 | 64 |
| 1996 | 71.4 |
| 1997 | 73.63 |
| 1998 | 73.3 |
| 1999 | 66.6 |
| 2000 | 67.5 |
| 2001 | 63.77 |
| 2002 | 60.91 |
| 2003 | 61.1 |
| 2004 | 62.79 |
| 2005 | 64.24 |
| 2006 | 62.68 |
| 2007 | 64.6 |
| 2008 | 64.97 |
| 2009 | |
| 2010 | 59.87 |
| 2011 | 59.91 |
| 2012 | 58.64 |
| 2013 | 56.03 |
| 2014 | 53.56 |
| 2015 | 51.41 |
| 2016 | 50.89 |
| 2017 | 45.97 |
| 2018 | 46.65 |