| 年度 | 实际值 |
|---|---|
| 1995 | 46.6 |
| 1996 | 42.8 |
| 1997 | 56.29 |
| 1998 | 39.7 |
| 1999 | 39.1 |
| 2000 | 39.8 |
| 2001 | 45.53 |
| 2002 | 50.28 |
| 2003 | 53.36 |
| 2004 | 55.32 |
| 2005 | 47.68 |
| 2006 | 55.6 |
| 2007 | 56.37 |
| 2008 | 58.75 |
| 2009 | |
| 2010 | 54.02 |
| 2011 | 55.01 |
| 2012 | 53.96 |
| 2013 | 53.99 |
| 2014 | 54.65 |
| 2015 | 55.78 |
| 2016 | 54.63 |
| 2017 | 54.72 |
| 2018 | 53.07 |