| 年度 | 实际值 |
|---|---|
| 1992 | 1.8 |
| 1993 | |
| 1994 | |
| 1995 | 1.8 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 1.9009 |
| 2000 | 2.0799 |
| 2001 | 1.9314 |
| 2002 | 2.1339 |
| 2003 | 2.1415 |
| 2004 | 2.123 |
| 2005 | 2.1457 |
| 2006 | 1.8192 |
| 2007 | 1.8884 |
| 2008 | 1.7845 |
| 2009 | 1.7414 |
| 2010 | 2.1156 |
| 2011 | 2.0952 |
| 2012 | 2.1945 |
| 2013 | 2.2093 |
| 2014 | 1.6384 |
| 2015 | 1.9377 |