| 年度 | 实际值 |
|---|---|
| 1993 | 20.3 |
| 1994 | |
| 1995 | 22.4 |
| 1996 | 23.4 |
| 1997 | 24.2 |
| 1998 | 25.5 |
| 1999 | 30.3 |
| 2000 | 30.1 |
| 2001 | 1.92 |
| 2002 | |
| 2003 | 27.84 |
| 2004 | 30.24 |
| 2005 | 32 |
| 2006 | 31.8 |
| 2007 | 38.9 |
| 2008 | 40.56 |
| 2009 | |
| 2010 | 40.98 |
| 2011 | 48.33 |
| 2012 | 46.55 |
| 2013 | 40.35 |
| 2014 | 40.41 |
| 2015 | 41.12 |
| 2016 | 40.81 |
| 2017 | 42.56 |
| 2018 | 46.82 |