| 年度 | 实际值 |
|---|---|
| 1995 | 58.5 |
| 1996 | 60.4 |
| 1997 | 59.16 |
| 1998 | 61.7 |
| 1999 | 62.4 |
| 2000 | 62.5 |
| 2001 | 62.25 |
| 2002 | 61.57 |
| 2003 | 61.49 |
| 2004 | 61.33 |
| 2005 | 52.41 |
| 2006 | 52.46 |
| 2007 | 51.86 |
| 2008 | 50.65 |
| 2009 | |
| 2010 | 49.11 |
| 2011 | 47.91 |
| 2012 | 47.19 |
| 2013 | 46.52 |
| 2014 | 45.9 |
| 2015 | 43.55 |
| 2016 | 42.75 |
| 2017 | 44.27 |
| 2018 | 44.9 |