| 年度 | 实际值 |
|---|---|
| 1993 | 17.4 |
| 1994 | |
| 1995 | 7.6 |
| 1996 | 10.8 |
| 1997 | 12 |
| 1998 | 12.2 |
| 1999 | 13.3 |
| 2000 | 17 |
| 2001 | 2.78666666666667 |
| 2002 | |
| 2003 | 34.96 |
| 2004 | 36.2 |
| 2005 | 36 |
| 2006 | 39.81 |
| 2007 | 42.83 |
| 2008 | 42.26 |
| 2009 | |
| 2010 | 42.6 |
| 2011 | 43.08 |
| 2012 | 43.02 |
| 2013 | 42.89 |
| 2014 | 43.28 |
| 2015 | 43.33 |
| 2016 | 43.08 |
| 2017 | 43.05 |
| 2018 | 43.29 |