| 年度 | 实际值 |
|---|---|
| 1993 | 8.9 |
| 1994 | |
| 1995 | 9.4 |
| 1996 | 11.8 |
| 1997 | 14.2 |
| 1998 | 15 |
| 1999 | 19.2 |
| 2000 | 20.4 |
| 2001 | 1.63333333333333 |
| 2002 | |
| 2003 | 29.88 |
| 2004 | 29.17 |
| 2005 | 37 |
| 2006 | 38.55 |
| 2007 | 42.17 |
| 2008 | 34.34 |
| 2009 | |
| 2010 | 42.34 |
| 2011 | 46.37 |
| 2012 | 45.98 |
| 2013 | 50.05 |
| 2014 | 50.05 |
| 2015 | 42.48 |
| 2016 | 36.98 |
| 2017 | 42.87 |
| 2018 | 40.16 |