| 年度 | 实际值 |
|---|---|
| 1992 | 33.8 |
| 1993 | |
| 1994 | |
| 1995 | 34.6 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 36.2 |
| 2000 | 36.6 |
| 2001 | 36.7757 |
| 2002 | 37.0261 |
| 2003 | 37.3512 |
| 2004 | 37.6335 |
| 2005 | 37.8438 |
| 2006 | 38.3029 |
| 2007 | 36.8745 |
| 2008 | 37.7757 |
| 2009 | 38.4773 |
| 2010 | 40 |
| 2011 | 41 |
| 2012 | 40 |
| 2013 | 40 |
| 2014 | 41 |
| 2015 | 42 |
| 2016 | 42 |
| 2017 | 41 |