| 年度 | 实际值 |
|---|---|
| 1992 | 49 |
| 1993 | |
| 1994 | |
| 1995 | 49.9 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 50.7 |
| 2000 | 51.3 |
| 2001 | 51.38 |
| 2002 | 51.39 |
| 2003 | 51.2 |
| 2004 | 50.82 |
| 2005 | 50.71 |
| 2006 | 50.97 |
| 2007 | 51.04 |
| 2008 | 51.32 |
| 2009 | 51.34 |
| 2010 | 51.02 |
| 2011 | 51.16 |
| 2012 | 50.92 |
| 2013 | 50.89 |
| 2014 | 50.97 |
| 2015 | 50.87 |
| 2016 | 50.9552 |
| 2017 | 51.1 |
| 2018 | 51.1184 |