| 年度 | 实际值 |
|---|---|
| 1995 | 42.9 |
| 1996 | 42.7 |
| 1997 | 42.97 |
| 1998 | 43.3 |
| 1999 | 42.7 |
| 2000 | 40.9 |
| 2001 | 40.81 |
| 2002 | 41.49 |
| 2003 | 42.35 |
| 2004 | 44.5 |
| 2005 | 42.25 |
| 2006 | 43.97 |
| 2007 | 44.96 |
| 2008 | 52.23 |
| 2009 | |
| 2010 | 53.6 |
| 2011 | 56.09 |
| 2012 | 56.13 |
| 2013 | 55.18 |
| 2014 | 54.2 |
| 2015 | 50.92 |
| 2016 | 48.23 |
| 2017 | |
| 2018 | 42.35 |