| 年度 | 实际值 |
|---|---|
| 1996 | 4.94 |
| 1997 | |
| 1998 | |
| 1999 | 4.8644 |
| 2000 | 4.5491 |
| 2001 | 4.45 |
| 2002 | 4.7348 |
| 2003 | 5.0209 |
| 2004 | 5.0182 |
| 2005 | 4.7198 |
| 2006 | 4.6665 |
| 2007 | 4.8003 |
| 2008 | 4.7865 |
| 2009 | 4.8182 |
| 2010 | 4.819 |
| 2011 | 4.8425 |
| 2012 | 4.8633 |
| 2013 | 4.8516 |
| 2014 | 4.8318 |
| 2015 | 4.6503 |
| 2016 | 4.6 |
| 2017 | 4.6 |
| 2018 | 4.5269 |