| 年度 | 实际值 |
|---|---|
| 1995 | 65.2 |
| 1996 | 69.6 |
| 1997 | 66.96 |
| 1998 | 61.2 |
| 1999 | 58.8 |
| 2000 | 58.1 |
| 2001 | 59.2 |
| 2002 | 59.99 |
| 2003 | 61.28 |
| 2004 | 62.74 |
| 2005 | 55.91 |
| 2006 | 59.04 |
| 2007 | 59.17 |
| 2008 | 61.56 |
| 2009 | |
| 2010 | 55.43 |
| 2011 | 56.61 |
| 2012 | 55.3 |
| 2013 | 53.77 |
| 2014 | 49.73 |
| 2015 | 45.54 |
| 2016 | 42.41 |
| 2017 | 42.49 |
| 2018 | 43.6 |