| 年度 | 实际值 |
|---|---|
| 1995 | 51.6 |
| 1996 | 53.8 |
| 1997 | 58.16 |
| 1998 | 56.7 |
| 1999 | 55.2 |
| 2000 | 54.8 |
| 2001 | 54.02 |
| 2002 | 54.35 |
| 2003 | 60.02 |
| 2004 | 63.3 |
| 2005 | 57.84 |
| 2006 | 58.69 |
| 2007 | 59.6 |
| 2008 | 63.47 |
| 2009 | |
| 2010 | 65.38 |
| 2011 | 67.89 |
| 2012 | 67.36 |
| 2013 | 65.01 |
| 2014 | 58.33 |
| 2015 | 51.13 |
| 2016 | 50.92 |
| 2017 | |
| 2018 | 54.19 |