| 年度 | 实际值 |
|---|---|
| 1993 | 24.1 |
| 1994 | |
| 1995 | 33.3 |
| 1996 | 34.8 |
| 1997 | 38.7 |
| 1998 | 39.8 |
| 1999 | 33.1 |
| 2000 | 45.5 |
| 2001 | 1.84666666666667 |
| 2002 | |
| 2003 | 46.35 |
| 2004 | 34 |
| 2005 | 32 |
| 2006 | 41.19 |
| 2007 | 40.46 |
| 2008 | 23.07 |
| 2009 | |
| 2010 | 37.78 |
| 2011 | 32.98 |
| 2012 | 34.72 |
| 2013 | 36 |
| 2014 | 36.95 |
| 2015 | 42.85 |
| 2016 | 42.94 |
| 2017 | 43.89 |
| 2018 | 43.4 |