| 年度 | 实际值 |
|---|---|
| 1992 | 50 |
| 1993 | |
| 1994 | |
| 1995 | 50.6 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 51.1 |
| 2000 | 51.21 |
| 2001 | 51.64 |
| 2002 | 51.73 |
| 2003 | 51.49 |
| 2004 | 51.89 |
| 2005 | 52.25 |
| 2006 | 52.61 |
| 2007 | 52.64 |
| 2008 | 52.65 |
| 2009 | 52.59 |
| 2010 | 52.59 |
| 2011 | 52.7 |
| 2012 | 52.6 |
| 2013 | 52.7 |
| 2014 | 52.97 |
| 2015 | 52.94 |
| 2016 | 53.1536 |
| 2017 | 53 |