| 年度 | 实际值 |
|---|---|
| 1993 | 32 |
| 1994 | |
| 1995 | 32.5 |
| 1996 | 42.2 |
| 1997 | 28.6 |
| 1998 | 33.1 |
| 1999 | 33.3 |
| 2000 | 34.1 |
| 2001 | 2.31333333333333 |
| 2002 | |
| 2003 | 36.03 |
| 2004 | 36.71 |
| 2005 | 41 |
| 2006 | 40.53 |
| 2007 | 41.57 |
| 2008 | 41.45 |
| 2009 | |
| 2010 | 42.31 |
| 2011 | 43.81 |
| 2012 | 43.96 |
| 2013 | 44.02 |
| 2014 | 43.87 |
| 2015 | 44.89 |
| 2016 | 44.9 |
| 2017 | 45.04 |
| 2018 | 45.05 |