| 年度 | 实际值 |
|---|---|
| 1992 | 7.5 |
| 1993 | |
| 1994 | |
| 1995 | 8.3 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 10.6566 |
| 2000 | 10.9412 |
| 2001 | 11.7974 |
| 2002 | 12.5899 |
| 2003 | 13.0489 |
| 2004 | 15.5512 |
| 2005 | 16.0401 |
| 2006 | 15.0504 |
| 2007 | 15.7233 |
| 2008 | 16.2289 |
| 2009 | 16.6063 |
| 2010 | 16.6426 |
| 2011 | 16.7502 |
| 2012 | 16.9408 |
| 2013 | 16.9408 |
| 2014 | 15.9742 |
| 2015 | 15.3489 |