| 年度 | 实际值 |
|---|---|
| 1993 | 30.7 |
| 1994 | |
| 1995 | 30.5 |
| 1996 | 30.5 |
| 1997 | 35.5 |
| 1998 | 34.9 |
| 1999 | 34.8 |
| 2000 | 35.2 |
| 2001 | 2.36 |
| 2002 | |
| 2003 | 19.96 |
| 2004 | 35.62 |
| 2005 | 35 |
| 2006 | 44.89 |
| 2007 | 44.04 |
| 2008 | 21.9 |
| 2009 | |
| 2010 | 36.58 |
| 2011 | 58.47 |
| 2012 | 38.17 |
| 2013 | 38.8 |
| 2014 | 39.78 |
| 2015 | |
| 2016 | 40.96 |
| 2017 | 42.83 |
| 2018 | 44.25 |