| 年度 | 实际值 |
|---|---|
| 1992 | 5.3 |
| 1993 | |
| 1994 | |
| 1995 | 5.4 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 5.8006 |
| 2000 | 5.8553 |
| 2001 | 5.6137 |
| 2002 | 5.6287 |
| 2003 | 5.6359 |
| 2004 | 5.6683 |
| 2005 | 5.6183 |
| 2006 | 5.6136 |
| 2007 | 5.5906 |
| 2008 | 6.8014 |
| 2009 | 7.11 |
| 2010 | 5.4556 |
| 2011 | 5.4528 |
| 2012 | 5.4366 |
| 2013 | 6.851 |
| 2014 | 6.4975 |
| 2015 | 6.5045 |