| 年度 | 实际值 |
|---|---|
| 1995 | 55.5 |
| 1996 | 58.8 |
| 1997 | 51.29 |
| 1998 | 52.6 |
| 1999 | 52.1 |
| 2000 | 50.1 |
| 2001 | 50.21 |
| 2002 | 50.6 |
| 2003 | 47.99 |
| 2004 | 51.9 |
| 2005 | 53.75 |
| 2006 | 55.7 |
| 2007 | 56.7 |
| 2008 | 56.83 |
| 2009 | |
| 2010 | 59.85 |
| 2011 | 65.24 |
| 2012 | 64.71 |
| 2013 | 62.39 |
| 2014 | 60.34 |
| 2015 | 58.35 |
| 2016 | 55.8 |
| 2017 | 54.41 |
| 2018 | 48.21 |