| 年度 | 实际值 |
|---|---|
| 1992 | 9.7 |
| 1993 | |
| 1994 | |
| 1995 | 9.9 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 10.6263 |
| 2000 | 11.2593 |
| 2001 | 11.0764 |
| 2002 | 11.6276 |
| 2003 | 15.0803 |
| 2004 | 13.9734 |
| 2005 | 14.3475 |
| 2006 | 16.2931 |
| 2007 | 15.8112 |
| 2008 | 16.4218 |
| 2009 | 18.1267 |
| 2010 | 19.6448 |
| 2011 | 19.283 |
| 2012 | 19.2975 |
| 2013 | 18.0009 |
| 2014 | 16.95 |
| 2015 | 16.647 |