| 年度 | 实际值 |
|---|---|
| 1993 | 30.6 |
| 1994 | |
| 1995 | 14.9 |
| 1996 | 15.2 |
| 1997 | 18.6 |
| 1998 | 18.7 |
| 1999 | 19 |
| 2000 | 19.9 |
| 2001 | 1.33333333333333 |
| 2002 | |
| 2003 | 19.75 |
| 2004 | 20.42 |
| 2005 | 28 |
| 2006 | 40.35 |
| 2007 | 42.09 |
| 2008 | 35.58 |
| 2009 | |
| 2010 | 42.31 |
| 2011 | 42.74 |
| 2012 | 42.71 |
| 2013 | 42.88 |
| 2014 | 42.77 |
| 2015 | 42.65 |
| 2016 | 43.17 |
| 2017 | 42.95 |
| 2018 | 42.96 |