| 年度 | 实际值 |
|---|---|
| 1995 | 38.2 |
| 1996 | 40.4 |
| 1997 | 38.58 |
| 1998 | 42.1 |
| 1999 | 42.1 |
| 2000 | 41.6 |
| 2001 | 41.41 |
| 2002 | 40.61 |
| 2003 | 43.78 |
| 2004 | 43.76 |
| 2005 | 53.34 |
| 2006 | 51.1 |
| 2007 | 50.69 |
| 2008 | 48.84 |
| 2009 | |
| 2010 | 48.01 |
| 2011 | 45.25 |
| 2012 | 45.69 |
| 2013 | 46.26 |
| 2014 | 45.84 |
| 2015 | 48.38 |
| 2016 | 51.94 |
| 2017 | 52.35 |
| 2018 | 56.49 |