| 年度 | 实际值 |
|---|---|
| 1992 | 11.7 |
| 1993 | |
| 1994 | |
| 1995 | 11.8 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 12.1 |
| 2000 | 11.9101 |
| 2001 | 12.012 |
| 2002 | 12.0049 |
| 2003 | 11.5102 |
| 2004 | 11.109 |
| 2005 | 11.6799 |
| 2006 | 12.6498 |
| 2007 | 12.1498 |
| 2008 | 11.9033 |
| 2009 | 11.1502 |
| 2010 | 11.7557 |
| 2011 | 11.7408 |
| 2012 | 11.2163 |
| 2013 | 11.7106 |
| 2014 | 11.6229 |
| 2015 | 11.4737 |