| 年度 | 实际值 |
|---|---|
| 1995 | 35.4 |
| 1996 | 4.6 |
| 1997 | 11.58 |
| 1998 | 6.1 |
| 1999 | 6.68 |
| 2000 | 11.3 |
| 2001 | 12 |
| 2002 | 9.4 |
| 2003 | 12.8 |
| 2004 | 22.5 |
| 2005 | 20.5 |
| 2006 | 16.5 |
| 2007 | 6.476660543 |
| 2008 | 9.22268547346383 |
| 2009 | 8.93731693559303 |
| 2010 | 14.9 |
| 2011 | 6.637328699253 |
| 2012 | 3.67495295588809 |
| 2013 | 13.3 |
| 2014 | 8.2 |
| 2015 | 8.2 |
| 2016 | |
| 2017 | 7.14 |
| 2018 | 5.59 |