| 年度 | 实际值 |
|---|---|
| 1995 | 71.2 |
| 1996 | 66.4 |
| 1997 | 72.04 |
| 1998 | 60.7 |
| 1999 | 59.2 |
| 2000 | 60.6 |
| 2001 | 59.26 |
| 2002 | 61.28 |
| 2003 | 62.95 |
| 2004 | 64.83 |
| 2005 | 66.27 |
| 2006 | 67.04 |
| 2007 | 68.03 |
| 2008 | 70.01 |
| 2009 | |
| 2010 | 58.66 |
| 2011 | 55.78 |
| 2012 | 52.37 |
| 2013 | 55.56 |
| 2014 | 51.2 |
| 2015 | 48.04 |
| 2016 | 45.76 |
| 2017 | 45.1 |
| 2018 | 44.19 |