| 年度 | 实际值 |
|---|---|
| 1995 | 4.8 |
| 1996 | 4.4 |
| 1997 | 7.9 |
| 1998 | 7.7 |
| 1999 | 8.3 |
| 2000 | 14.2 |
| 2001 | .953333333333333 |
| 2002 | |
| 2003 | 18.21 |
| 2004 | 18.74 |
| 2005 | 21 |
| 2006 | 65.41 |
| 2007 | 68.44 |
| 2008 | 67.91 |
| 2009 | |
| 2010 | 43.05 |
| 2011 | 32.9 |
| 2012 | 38.84 |
| 2013 | 39 |
| 2014 | 39.45 |
| 2015 | 40.06 |
| 2016 | 43.09 |
| 2017 | 40.33 |
| 2018 | 40.53 |