| 年度 | 实际值 |
|---|---|
| 1995 | 46.7 |
| 1996 | 47.7 |
| 1997 | 49.06 |
| 1998 | 49.4 |
| 1999 | 46.4 |
| 2000 | 47.4 |
| 2001 | 47.89 |
| 2002 | 45.53 |
| 2003 | 46.51 |
| 2004 | 46.43 |
| 2005 | 39.98 |
| 2006 | 43.06 |
| 2007 | 43.6 |
| 2008 | 44.98 |
| 2009 | |
| 2010 | 51.89 |
| 2011 | 57.08 |
| 2012 | 57.08 |
| 2013 | 57.26 |
| 2014 | 57.67 |
| 2015 | 56.86 |
| 2016 | 55.4 |
| 2017 | |
| 2018 | 51.47 |