| 年度 | 实际值 |
|---|---|
| 1995 | 45.7 |
| 1996 | 45.9 |
| 1997 | 46.24 |
| 1998 | 45.9 |
| 1999 | 44.5 |
| 2000 | 46.1 |
| 2001 | 45.99 |
| 2002 | 47.33 |
| 2003 | 50.49 |
| 2004 | 54.84 |
| 2005 | 56.86 |
| 2006 | 58.15 |
| 2007 | 58.11 |
| 2008 | 58.39 |
| 2009 | |
| 2010 | 55.66 |
| 2011 | 55.38 |
| 2012 | 53.99 |
| 2013 | 51.97 |
| 2014 | 50.81 |
| 2015 | 48.17 |
| 2016 | 48.17 |
| 2017 | |
| 2018 | 44.54 |