| 年度 | 实际值 |
|---|---|
| 1992 | 9.1 |
| 1993 | |
| 1994 | |
| 1995 | 9 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 11.2878 |
| 2000 | 11.9388 |
| 2001 | 12.1166 |
| 2002 | 12.1259 |
| 2003 | 12.1855 |
| 2004 | 10.252 |
| 2005 | 12.2403 |
| 2006 | 13.0346 |
| 2007 | 13.3352 |
| 2008 | 13.1835 |
| 2009 | 11.6038 |
| 2010 | 13.1717 |
| 2011 | 13.6995 |
| 2012 | 13.6851 |
| 2013 | 13.3318 |
| 2014 | 13.439 |
| 2015 | 13.5607 |