| 年度 | 实际值 |
|---|---|
| 1995 | 58.5 |
| 1996 | 45.1 |
| 1997 | 43.54 |
| 1998 | 45.1 |
| 1999 | 45.5 |
| 2000 | 43.8 |
| 2001 | 42.07 |
| 2002 | 42.69 |
| 2003 | 46.78 |
| 2004 | 50.09 |
| 2005 | 45.71 |
| 2006 | 48.95 |
| 2007 | 51.77 |
| 2008 | 53.86 |
| 2009 | |
| 2010 | 51.05 |
| 2011 | 53.36 |
| 2012 | 51.64 |
| 2013 | 52.58 |
| 2014 | 49.79 |
| 2015 | 48.03 |
| 2016 | 47.72 |
| 2017 | |
| 2018 | 36.38 |