| 年度 | 实际值 |
|---|---|
| 1995 | 45.6 |
| 1996 | 47.2 |
| 1997 | 50.05 |
| 1998 | 51.2 |
| 1999 | 47.4 |
| 2000 | 44.9 |
| 2001 | 49.24 |
| 2002 | 49.41 |
| 2003 | 52.06 |
| 2004 | 57.11 |
| 2005 | 58.44 |
| 2006 | 61.92 |
| 2007 | 60.67 |
| 2008 | 61.84 |
| 2009 | |
| 2010 | 56.56 |
| 2011 | 58.32 |
| 2012 | 59.18 |
| 2013 | 56.03 |
| 2014 | 54.09 |
| 2015 | 45.09 |
| 2016 | 43.05 |
| 2017 | |
| 2018 | 38.25 |