| 年度 | 实际值 |
|---|---|
| 1993 | 26.1 |
| 1994 | |
| 1995 | 22.5 |
| 1996 | 23.4 |
| 1997 | 23.1 |
| 1998 | 22.4 |
| 1999 | 22.6 |
| 2000 | 21.8 |
| 2001 | 1.47333333333333 |
| 2002 | |
| 2003 | 18.06 |
| 2004 | 22.35 |
| 2005 | 22 |
| 2006 | 23.46 |
| 2007 | 31.83 |
| 2008 | 68.94 |
| 2009 | |
| 2010 | 42.57 |
| 2011 | 40.18 |
| 2012 | 42.92 |
| 2013 | 41.66 |
| 2014 | 41.02 |
| 2015 | 40.32 |
| 2016 | 40.75 |
| 2017 | 40 |
| 2018 | 40.35 |