| 年度 | 实际值 |
|---|---|
| 1995 | 53.5 |
| 1996 | 54.9 |
| 1997 | 54.65 |
| 1998 | 57.1 |
| 1999 | 55.1 |
| 2000 | 56.7 |
| 2001 | 58.78 |
| 2002 | 59.8 |
| 2003 | 59.78 |
| 2004 | 59.05 |
| 2005 | 57.75 |
| 2006 | 58.56 |
| 2007 | 58.08 |
| 2008 | 57.87 |
| 2009 | |
| 2010 | 58.01 |
| 2011 | 66.86 |
| 2012 | 59.88 |
| 2013 | 59.61 |
| 2014 | 59.21 |
| 2015 | 57.73 |
| 2016 | 56.33 |
| 2017 | 44.54 |
| 2018 | 43.02 |