| 年度 | 实际值 |
|---|---|
| 1993 | 26.2 |
| 1994 | |
| 1995 | 37.8 |
| 1996 | 31.5 |
| 1997 | 38 |
| 1998 | 38 |
| 1999 | 38.7 |
| 2000 | 38 |
| 2001 | 2.57333333333333 |
| 2002 | |
| 2003 | 40.09 |
| 2004 | 54.55 |
| 2005 | 50 |
| 2006 | 53.42 |
| 2007 | 40.89 |
| 2008 | 40.85 |
| 2009 | |
| 2010 | 52.83 |
| 2011 | 46.71 |
| 2012 | 61.02 |
| 2013 | 45.97 |
| 2014 | 46.71 |
| 2015 | 45.72 |
| 2016 | 48.69 |
| 2017 | 48.5 |
| 2018 | 44.95 |