| 年度 | 实际值 |
|---|---|
| 1992 | 33.1 |
| 1993 | |
| 1994 | |
| 1995 | 33.6 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 33.9 |
| 2000 | 34.06 |
| 2001 | 34.17 |
| 2002 | 34.28 |
| 2003 | 34.36 |
| 2004 | 34.28 |
| 2005 | 34.5 |
| 2006 | 34.66 |
| 2007 | 34.86 |
| 2008 | 34.99 |
| 2009 | 35.06 |
| 2010 | 35.2 |
| 2011 | 35.43 |
| 2012 | 35.48 |
| 2013 | 35.63 |
| 2014 | 35.82 |
| 2015 | 35.99 |
| 2016 | 35.9748 |
| 2017 | 36 |