| 年度 | 实际值 |
|---|---|
| 1992 | 33.6 |
| 1993 | |
| 1994 | |
| 1995 | 34.1 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 34.2 |
| 2000 | 34.38 |
| 2001 | 34.3152 |
| 2002 | 34.3182 |
| 2003 | 34.2912 |
| 2004 | 34.392 |
| 2005 | 36.4 |
| 2006 | 36.18 |
| 2007 | 35.18 |
| 2008 | 35.29 |
| 2009 | 35.0191 |
| 2010 | 34.7913 |
| 2011 | 34.9994 |
| 2012 | 35.0751 |
| 2013 | 35.2293 |
| 2014 | 32.6 |
| 2015 | 32.66 |
| 2016 | 34 |
| 2017 | 34 |