| 年度 | 实际值 |
|---|---|
| 1995 | 47.3 |
| 1996 | 46.3 |
| 1997 | 45.96 |
| 1998 | 45.4 |
| 1999 | 46.1 |
| 2000 | 46.6 |
| 2001 | 46.47 |
| 2002 | 47.02 |
| 2003 | 47.93 |
| 2004 | 50.12 |
| 2005 | 46.28 |
| 2006 | 47.83 |
| 2007 | 49.05 |
| 2008 | 51.68 |
| 2009 | |
| 2010 | 50.88 |
| 2011 | 52.1 |
| 2012 | 51.9 |
| 2013 | 50.87 |
| 2014 | 48.3 |
| 2015 | 43.31 |
| 2016 | 41.85 |
| 2017 | |
| 2018 | 42.27 |