| 年度 | 实际值 |
|---|---|
| 1993 | 4.9 |
| 1994 | |
| 1995 | 21.9 |
| 1996 | 22 |
| 1997 | 32 |
| 1998 | 31.4 |
| 1999 | 31.5 |
| 2000 | 30.7 |
| 2001 | 2.04666666666667 |
| 2002 | |
| 2003 | 31.74 |
| 2004 | 31.74 |
| 2005 | 34 |
| 2006 | 34.46 |
| 2007 | 46.81 |
| 2008 | 35.51 |
| 2009 | |
| 2010 | 34.96 |
| 2011 | 35.45 |
| 2012 | 37.53 |
| 2013 | 25.3 |
| 2014 | 29.57 |
| 2015 | 29.63 |
| 2016 | 40.69 |
| 2017 | 43 |
| 2018 | 41.17 |