| 年度 | 实际值 |
|---|---|
| 1995 | 48.6 |
| 1996 | 52.1 |
| 1997 | 53.59 |
| 1998 | 50.8 |
| 1999 | |
| 2000 | 48.4 |
| 2001 | 54.13 |
| 2002 | 53.13 |
| 2003 | 50.76 |
| 2004 | 47.14 |
| 2005 | 49.77 |
| 2006 | 50 |
| 2007 | 52.29 |
| 2008 | 51.82 |
| 2009 | |
| 2010 | 50.42 |
| 2011 | 44.34 |
| 2012 | 44.67 |
| 2013 | 43.43 |
| 2014 | 42.94 |
| 2015 | 46.23 |
| 2016 | 46.27 |
| 2017 | 46.49 |
| 2018 | 47.8 |