| 年度 | 实际值 |
|---|---|
| 1995 | 41.3 |
| 1996 | 42.3 |
| 1997 | 58.43 |
| 1998 | 44.6 |
| 1999 | 46.8 |
| 2000 | 47.1 |
| 2001 | 45.9 |
| 2002 | 44.99 |
| 2003 | 43.51 |
| 2004 | 40.21 |
| 2005 | 44.01 |
| 2006 | 42.17 |
| 2007 | 40.45 |
| 2008 | 40.48 |
| 2009 | |
| 2010 | 41.26 |
| 2011 | 40.29 |
| 2012 | 41.41 |
| 2013 | 40.03 |
| 2014 | 40.99 |
| 2015 | 43.08 |
| 2016 | 44.24 |
| 2017 | 45.32 |
| 2018 | 45.5 |