| 年度 | 实际值 |
|---|---|
| 1993 | 5 |
| 1994 | |
| 1995 | 13.8 |
| 1996 | 15.1 |
| 1997 | 14 |
| 1998 | 15.9 |
| 1999 | 17.2 |
| 2000 | 20.5 |
| 2001 | 1.16666666666667 |
| 2002 | |
| 2003 | 36.01 |
| 2004 | 36.04 |
| 2005 | 36 |
| 2006 | 39.2 |
| 2007 | 38.88 |
| 2008 | 38.85 |
| 2009 | |
| 2010 | 39.16 |
| 2011 | 39.55 |
| 2012 | 40.39 |
| 2013 | 42.71 |
| 2014 | 44.25 |
| 2015 | 44.25 |
| 2016 | 43.53 |
| 2017 | 41.57 |
| 2018 | 41.96 |