| 年度 | 实际值 |
|---|---|
| 1992 | 10 |
| 1993 | |
| 1994 | |
| 1995 | 10.2 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 10.3316 |
| 2000 | 10.2211 |
| 2001 | 10.1484 |
| 2002 | 10.0489 |
| 2003 | 10.0767 |
| 2004 | 10.0916 |
| 2005 | 9.4541 |
| 2006 | 9.9566 |
| 2007 | 10.2223 |
| 2008 | 10.376 |
| 2009 | 10.5149 |
| 2010 | 10.5225 |
| 2011 | 10.6958 |
| 2012 | 10.9011 |
| 2013 | 11.0308 |
| 2014 | 11.0348 |
| 2015 | 10.9794 |
| 2016 | 11 |
| 2017 | 11 |