| 年度 | 实际值 |
|---|---|
| 1995 | 47.1 |
| 1996 | 46.3 |
| 1997 | 46.49 |
| 1998 | 46.7 |
| 1999 | 47.1 |
| 2000 | 48.4 |
| 2001 | 48.71 |
| 2002 | 49.64 |
| 2003 | 52.28 |
| 2004 | 53.44 |
| 2005 | 51.38 |
| 2006 | 54.51 |
| 2007 | 55.89 |
| 2008 | 57.47 |
| 2009 | |
| 2010 | 55.33 |
| 2011 | 55.02 |
| 2012 | 53.5 |
| 2013 | 52.72 |
| 2014 | 50.25 |
| 2015 | 48.05 |
| 2016 | 40.77 |
| 2017 | |
| 2018 | 44.38 |