| 年度 | 实际值 |
|---|---|
| 1992 | 5.8 |
| 1993 | |
| 1994 | |
| 1995 | 5.7 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 5.7 |
| 2000 | 5.7378 |
| 2001 | 5.7514 |
| 2002 | 5.7465 |
| 2003 | 5.6844 |
| 2004 | 5.7531 |
| 2005 | 4.89 |
| 2006 | 4.8992 |
| 2007 | 4.9 |
| 2008 | 4.9129 |
| 2009 | 5.9437 |
| 2010 | 5.9598 |
| 2011 | 5.9162 |
| 2012 | 5.9597 |
| 2013 | 6.0075 |
| 2014 | 5.12 |
| 2015 | 5.1386 |
| 2016 | 6 |
| 2017 | 6 |