| 年度 | 实际值 |
|---|---|
| 1995 | 20.1 |
| 1996 | 10.3 |
| 1997 | 13.38 |
| 1998 | 23.1 |
| 1999 | 6.52 |
| 2000 | 12.3 |
| 2001 | 20 |
| 2002 | 22.9 |
| 2003 | 29.5 |
| 2004 | 28.9 |
| 2005 | 32.3 |
| 2006 | 35.9 |
| 2007 | 23.7059796055218 |
| 2008 | 11.0234279532609 |
| 2009 | 20.8 |
| 2010 | 18.5 |
| 2011 | 11.4 |
| 2012 | 12.5 |
| 2013 | 11. |
| 2014 | 14.3 |
| 2015 | 11.8962524169427 |
| 2016 | |
| 2017 | 4.8 |
| 2018 | 6.8 |