| 年度 | 实际值 |
|---|---|
| 1995 | 39.4 |
| 1996 | 40.6 |
| 1997 | 39.84 |
| 1998 | 42.3 |
| 1999 | 45.7 |
| 2000 | 43.6 |
| 2001 | 45.99 |
| 2002 | 46 |
| 2003 | 41.95 |
| 2004 | 43.35 |
| 2005 | 42.5 |
| 2006 | 47.87 |
| 2007 | 49.31 |
| 2008 | 43.61 |
| 2009 | |
| 2010 | 52.12 |
| 2011 | 44.29 |
| 2012 | 47.51 |
| 2013 | 48.42 |
| 2014 | 49.07 |
| 2015 | 52.37 |
| 2016 | 50.94 |
| 2017 | 48.77 |
| 2018 | 47.43 |