| 年度 | 实际值 |
|---|---|
| 1992 | 42.72 |
| 1993 | 43.15 |
| 1994 | 43.75 |
| 1995 | 44.43 |
| 1996 | 44.81 |
| 1997 | 45.39 |
| 1998 | 45.17 |
| 1999 | 44.96 |
| 2000 | 44.82 |
| 2001 | 44.68 |
| 2002 | 44.7 |
| 2003 | 44.67 |
| 2004 | 44.5 |
| 2005 | 47.86 |
| 2006 | 47.78 |
| 2007 | 47.74 |
| 2008 | 47.73 |
| 2009 | 47.79 |
| 2010 | 47.86 |
| 2011 | 47.34 |
| 2012 | 47.32 |
| 2013 | 47.35 |
| 2014 | 47.22 |
| 2015 | 46.61 |
| 2016 | 46 |
| 2017 | 45 |
| 2018 | 45 |