| 年度 | 实际值 |
|---|---|
| 1995 | 62.2 |
| 1996 | 63.4 |
| 1997 | 40.86 |
| 1998 | 59.1 |
| 1999 | 56.1 |
| 2000 | 56.3 |
| 2001 | 47.64 |
| 2002 | 46.06 |
| 2003 | 48.61 |
| 2004 | 51.56 |
| 2005 | 52.94 |
| 2006 | 56.34 |
| 2007 | 58.62 |
| 2008 | 55.91 |
| 2009 | |
| 2010 | 62.2 |
| 2011 | 64.88 |
| 2012 | 65.77 |
| 2013 | 67.72 |
| 2014 | 63.61 |
| 2015 | 59.22 |
| 2016 | 51.27 |
| 2017 | 50.95 |
| 2018 | 43.24 |