| 年度 | 实际值 |
|---|---|
| 1993 | 38.1 |
| 1994 | |
| 1995 | 39 |
| 1996 | 40.1 |
| 1997 | 38.9 |
| 1998 | 40.3 |
| 1999 | 40.7 |
| 2000 | 41.3 |
| 2001 | 2.83333333333333 |
| 2002 | |
| 2003 | 42.78 |
| 2004 | 42 |
| 2005 | 42 |
| 2006 | 42.25 |
| 2007 | 40.36 |
| 2008 | 42.32 |
| 2009 | |
| 2010 | 42.29 |
| 2011 | 43.01 |
| 2012 | 43.63 |
| 2013 | 43.82 |
| 2014 | 43.78 |
| 2015 | 44.09 |
| 2016 | 44.2 |
| 2017 | 44.11 |
| 2018 | 44.19 |