| 年度 | 实际值 |
|---|---|
| 1995 | 63.6 |
| 1996 | 63.6 |
| 1997 | 69.67 |
| 1998 | 58.4 |
| 1999 | 57.2 |
| 2000 | 53 |
| 2001 | 52.36 |
| 2002 | 52.15 |
| 2003 | 51.92 |
| 2004 | 54.61 |
| 2005 | 46.63 |
| 2006 | 47.96 |
| 2007 | 45.8 |
| 2008 | 46.52 |
| 2009 | |
| 2010 | 46.27 |
| 2011 | 45.72 |
| 2012 | 48.2 |
| 2013 | 45.34 |
| 2014 | 37.6 |
| 2015 | 34.66 |
| 2016 | 32.43 |
| 2017 | 32.59 |
| 2018 | 31.45 |