| 年度 | 实际值 |
|---|---|
| 1992 | 1.5 |
| 1993 | |
| 1994 | |
| 1995 | 1.5 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 1.6571 |
| 2000 | 1.7337 |
| 2001 | 1.7342 |
| 2002 | 1.6613 |
| 2003 | 1.5797 |
| 2004 | 1.8324 |
| 2005 | 1.91 |
| 2006 | 2.1888 |
| 2007 | 2.2651 |
| 2008 | 2.2137 |
| 2009 | 2.2185 |
| 2010 | 2.0246 |
| 2011 | 2.2742 |
| 2012 | 1.9614 |
| 2013 | 2.1842 |
| 2014 | 2.2507 |
| 2015 | 2.2943 |