| 年度 | 实际值 |
|---|---|
| 1992 | 22.5 |
| 1993 | |
| 1994 | |
| 1995 | 22.8 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 21.95 |
| 2000 | 220197 |
| 2001 | 219823 |
| 2002 | 18.2934 |
| 2003 | 18.5775 |
| 2004 | 18.4149 |
| 2005 | 18.4466 |
| 2006 | 18.45 |
| 2007 | 18.69 |
| 2008 | 18.7 |
| 2009 | 20.0225 |
| 2010 | 19.5478 |
| 2011 | 19.5366 |
| 2012 | 19.79 |
| 2013 | 19.6 |
| 2014 | 19.66 |
| 2015 | 18.25 |
| 2016 | 18.25 |