| 年度 | 实际值 |
|---|---|
| 1992 | 7.2 |
| 1993 | |
| 1994 | |
| 1995 | 7 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 9.4145 |
| 2000 | 9.5217 |
| 2001 | 10.0265 |
| 2002 | 10.2733 |
| 2003 | 9.8711 |
| 2004 | 10.2106 |
| 2005 | 11.1334 |
| 2006 | 11.4883 |
| 2007 | 11.5467 |
| 2008 | 11.2765 |
| 2009 | 11.9564 |
| 2010 | 12.4288 |
| 2011 | 11.9874 |
| 2012 | 12.0891 |
| 2013 | 11.9295 |
| 2014 | 13.4681 |
| 2015 | 13.719 |