| 年度 | 实际值 |
|---|---|
| 1995 | 58.1 |
| 1996 | 43 |
| 1997 | 26.19 |
| 1998 | 44 |
| 1999 | 39.3 |
| 2000 | 47.4 |
| 2001 | 44.3 |
| 2002 | 44.6 |
| 2003 | 46.84 |
| 2004 | 45.95 |
| 2005 | 46.95 |
| 2006 | 49.49 |
| 2007 | 52.31 |
| 2008 | 55.86 |
| 2009 | |
| 2010 | 58.37 |
| 2011 | 65.71 |
| 2012 | 66.45 |
| 2013 | 65.88 |
| 2014 | 65.88 |
| 2015 | 65.68 |
| 2016 | 64.57 |
| 2017 | 57.72 |
| 2018 | 56.33 |