| 年度 | 实际值 |
|---|---|
| 1993 | 22.6 |
| 1994 | |
| 1995 | 27.6 |
| 1996 | 27.6 |
| 1997 | 29.9 |
| 1998 | 30.9 |
| 1999 | 31.9 |
| 2000 | 34.6 |
| 2001 | 2.71333333333333 |
| 2002 | |
| 2003 | 41.91 |
| 2004 | 42.3 |
| 2005 | 43 |
| 2006 | 42.97 |
| 2007 | 43.88 |
| 2008 | 44.27 |
| 2009 | |
| 2010 | 45 |
| 2011 | 49.32 |
| 2012 | 49.3 |
| 2013 | 46.42 |
| 2014 | 46.52 |
| 2015 | 46.64 |
| 2016 | 44.76 |
| 2017 | 44.71 |
| 2018 | 42.76 |