| 年度 | 实际值 |
|---|---|
| 1995 | 48 |
| 1996 | 50.6 |
| 1997 | 47.65 |
| 1998 | 55.2 |
| 1999 | |
| 2000 | 54.6 |
| 2001 | 54.04 |
| 2002 | 49.73 |
| 2003 | 51.79 |
| 2004 | 51.67 |
| 2005 | 52.65 |
| 2006 | 53.91 |
| 2007 | 54.24 |
| 2008 | 53.86 |
| 2009 | |
| 2010 | 54.05 |
| 2011 | 54.46 |
| 2012 | 53.97 |
| 2013 | 53.15 |
| 2014 | 50.01 |
| 2015 | 47.93 |
| 2016 | 46.4 |
| 2017 | 46.95 |
| 2018 | 45.38 |