| 年度 | 实际值 |
|---|---|
| 1993 | 11.6 |
| 1994 | |
| 1995 | 11.6 |
| 1996 | 13.3 |
| 1997 | 13.4 |
| 1998 | 49.1 |
| 1999 | 56.2 |
| 2000 | 52.4 |
| 2001 | 3.55333333333333 |
| 2002 | |
| 2003 | 39.86 |
| 2004 | 40.18 |
| 2005 | 41 |
| 2006 | 38.44 |
| 2007 | 44.22 |
| 2008 | 44.56 |
| 2009 | |
| 2010 | 43.33 |
| 2011 | 42.17 |
| 2012 | 44.29 |
| 2013 | 27.31 |
| 2014 | 22.1 |
| 2015 | 24.38 |
| 2016 | 26.62 |
| 2017 | 39.56 |
| 2018 | 37.95 |