| 年度 | 实际值 |
|---|---|
| 1992 | 5 |
| 1993 | |
| 1994 | |
| 1995 | 4.9 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 5.1 |
| 2000 | 5.1664 |
| 2001 | 5.1918 |
| 2002 | 5.1961 |
| 2003 | 5.1892 |
| 2004 | 5.2019 |
| 2005 | 5.48 |
| 2006 | 5.49 |
| 2007 | 5.18 |
| 2008 | 5.1795 |
| 2009 | 5.187 |
| 2010 | 5.1629 |
| 2011 | 5.1539 |
| 2012 | 5.0655 |
| 2013 | 5.0688 |
| 2014 | 5.14 |
| 2015 | 5.15666996297378 |
| 2016 | 5 |
| 2017 | 5 |