| 年度 | 实际值 |
|---|---|
| 1995 | 44.8 |
| 1996 | 42 |
| 1997 | 43.25 |
| 1998 | 31.8 |
| 1999 | 30.5 |
| 2000 | 30.7 |
| 2001 | 30.22 |
| 2002 | 30.9 |
| 2003 | 35.47 |
| 2004 | 36.93 |
| 2005 | 39.36 |
| 2006 | 41.22 |
| 2007 | 42.62 |
| 2008 | 45.24 |
| 2009 | |
| 2010 | 44.61 |
| 2011 | 46.69 |
| 2012 | 46.97 |
| 2013 | 47.82 |
| 2014 | 47.35 |
| 2015 | 46.37 |
| 2016 | 44.61 |
| 2017 | |
| 2018 | 31.04 |