| 年度 | 实际值 |
|---|---|
| 1993 | 23.5 |
| 1994 | |
| 1995 | 25 |
| 1996 | 25.4 |
| 1997 | |
| 1998 | |
| 1999 | |
| 2000 | 26 |
| 2001 | 1.05333333333333 |
| 2002 | |
| 2003 | 21.16 |
| 2004 | 23.97 |
| 2005 | 26 |
| 2006 | 27.19 |
| 2007 | 28.7 |
| 2008 | 45.81 |
| 2009 | |
| 2010 | 31.73 |
| 2011 | 40.02 |
| 2012 | 37.39 |
| 2013 | 37.91 |
| 2014 | 37.37 |
| 2015 | 37.8 |
| 2016 | 38.31 |
| 2017 | 38.37 |
| 2018 | 38.68 |