| 年度 | 实际值 |
|---|---|
| 1995 | 48.5 |
| 1996 | 43.1 |
| 1997 | 33.41 |
| 1998 | 37.6 |
| 1999 | |
| 2000 | 37.6 |
| 2001 | 31.98 |
| 2002 | 33.33 |
| 2003 | 40.7 |
| 2004 | 40.61 |
| 2005 | 39.71 |
| 2006 | 42.37 |
| 2007 | 43.77 |
| 2008 | 42.9 |
| 2009 | |
| 2010 | 43.99 |
| 2011 | 46.77 |
| 2012 | 47.52 |
| 2013 | 48.14 |
| 2014 | 47.77 |
| 2015 | 46.73 |
| 2016 | 45.78 |
| 2017 | 44.99 |
| 2018 | 43.47 |