| 年度 | 实际值 |
|---|---|
| 1995 | 48.6 |
| 1996 | 46.8 |
| 1997 | 46.26 |
| 1998 | 44.7 |
| 1999 | 44.1 |
| 2000 | 44.2 |
| 2001 | 44.13 |
| 2002 | 44.24 |
| 2003 | 44.63 |
| 2004 | 46.17 |
| 2005 | 45.53 |
| 2006 | 46.15 |
| 2007 | 45.83 |
| 2008 | 46.15 |
| 2009 | |
| 2010 | 45.51 |
| 2011 | 48.12 |
| 2012 | 48.35 |
| 2013 | 48.57 |
| 2014 | 47.53 |
| 2015 | 45.68 |
| 2016 | 43.88 |
| 2017 | |
| 2018 | 42.96 |