| 年度 | 实际值 |
|---|---|
| 1993 | 16.8 |
| 1994 | |
| 1995 | 26.5 |
| 1996 | 26.7 |
| 1997 | 28.8 |
| 1998 | 24.7 |
| 1999 | 25.2 |
| 2000 | 25.3 |
| 2001 | 1.72 |
| 2002 | |
| 2003 | 33.4 |
| 2004 | 38.26 |
| 2005 | 40 |
| 2006 | 41.94 |
| 2007 | 40.13 |
| 2008 | 40.2 |
| 2009 | |
| 2010 | 40.59 |
| 2011 | 41 |
| 2012 | 41.06 |
| 2013 | 40.72 |
| 2014 | 40.81 |
| 2015 | 41.3 |
| 2016 | 41.82 |
| 2017 | 42.22 |
| 2018 | 43 |