| 年度 | 实际值 |
|---|---|
| 1993 | 29.1 |
| 1994 | |
| 1995 | 5.7 |
| 1996 | 32.6 |
| 1997 | 39.7 |
| 1998 | 39.5 |
| 1999 | 31 |
| 2000 | 31.5 |
| 2001 | 2.09333333333333 |
| 2002 | |
| 2003 | 34.95 |
| 2004 | 35.2 |
| 2005 | 35 |
| 2006 | 38.32 |
| 2007 | 38.11 |
| 2008 | 34.66 |
| 2009 | |
| 2010 | 39.05 |
| 2011 | 39.43 |
| 2012 | 46.66 |
| 2013 | 59 |
| 2014 | 45.04 |
| 2015 | 44.9 |
| 2016 | 36.88 |
| 2017 | 32.24 |
| 2018 | 32.21 |