| 年度 | 实际值 |
|---|---|
| 1995 | 47.4 |
| 1996 | 40.3 |
| 1997 | 39.73 |
| 1998 | 40.3 |
| 1999 | 39.4 |
| 2000 | 42.3 |
| 2001 | 44.01 |
| 2002 | 44.04 |
| 2003 | 45.49 |
| 2004 | 45.83 |
| 2005 | 36.25 |
| 2006 | 36.59 |
| 2007 | 38.08 |
| 2008 | 39.76 |
| 2009 | |
| 2010 | 48.37 |
| 2011 | 52.45 |
| 2012 | 54.14 |
| 2013 | 54.21 |
| 2014 | 53.91 |
| 2015 | 52.55 |
| 2016 | 51.91 |
| 2017 | |
| 2018 | 51.08 |