| 年度 | 实际值 |
|---|---|
| 1992 | 11.1 |
| 1993 | |
| 1994 | |
| 1995 | 11.6 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 11.7 |
| 2000 | 12.0034 |
| 2001 | 14.0375 |
| 2002 | 14.221 |
| 2003 | 13.8505 |
| 2004 | 12.9865 |
| 2005 | 14.8877 |
| 2006 | 15.4235 |
| 2007 | 15.3416 |
| 2008 | 14.8446 |
| 2009 | 14.9343 |
| 2010 | 18.6814 |
| 2011 | 18.0176 |
| 2012 | 18.5039 |
| 2013 | 16.316 |
| 2014 | 16.2765 |
| 2015 | 19.783 |