| 年度 | 实际值 |
|---|---|
| 1993 | 32.7 |
| 1994 | |
| 1995 | 37.4 |
| 1996 | 43 |
| 1997 | 39.7 |
| 1998 | 43.9 |
| 1999 | 36 |
| 2000 | 35.1 |
| 2001 | 2.34666666666667 |
| 2002 | |
| 2003 | 40.89 |
| 2004 | 42.75 |
| 2005 | 44 |
| 2006 | 40.94 |
| 2007 | 41.97 |
| 2008 | 41.08 |
| 2009 | |
| 2010 | 39.53 |
| 2011 | 40.65 |
| 2012 | 40.45 |
| 2013 | 40.52 |
| 2014 | 40.81 |
| 2015 | 41.23 |
| 2016 | 41.84 |
| 2017 | 45.81 |
| 2018 | 45.81 |