| 年度 | 实际值 |
|---|---|
| 1992 | 35.1 |
| 1993 | |
| 1994 | |
| 1995 | 36.5 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 37.9 |
| 2000 | 38.5136 |
| 2001 | 38.5853 |
| 2002 | 38.455 |
| 2003 | 38.1133 |
| 2004 | 38.7635 |
| 2005 | 38.92 |
| 2006 | 38.76 |
| 2007 | 38.46 |
| 2008 | 38.53 |
| 2009 | 40.1076 |
| 2010 | 40.4663 |
| 2011 | 40.663 |
| 2012 | 40.4458 |
| 2013 | 40.7018 |
| 2014 | 39.03 |
| 2015 | 39.1534525547445 |
| 2016 | 39 |
| 2017 | 39 |