| 年度 | 实际值 |
|---|---|
| 1992 | 52.2 |
| 1993 | |
| 1994 | |
| 1995 | 53.1 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 55.1 |
| 2000 | 55.44 |
| 2001 | 55.47 |
| 2002 | 55.52 |
| 2003 | 55.52 |
| 2004 | 55.66 |
| 2005 | 55.88 |
| 2006 | 56.26 |
| 2007 | 56.5 |
| 2008 | 56.89 |
| 2009 | 57.5 |
| 2010 | 58.16 |
| 2011 | 58.62 |
| 2012 | 59.22 |
| 2013 | 59.54 |
| 2014 | 59.84 |
| 2015 | 59.37 |
| 2016 | 59.8493 |
| 2017 | 60 |