| 年度 | 实际值 |
|---|---|
| 1995 | 44.8 |
| 1996 | 41.1 |
| 1997 | 42.96 |
| 1998 | 43.3 |
| 1999 | |
| 2000 | 45.7 |
| 2001 | 39.88 |
| 2002 | 41.08 |
| 2003 | 44.59 |
| 2004 | 46.09 |
| 2005 | 43.46 |
| 2006 | 42.8 |
| 2007 | 41.28 |
| 2008 | 41.69 |
| 2009 | |
| 2010 | 42.83 |
| 2011 | 50.16 |
| 2012 | 50.02 |
| 2013 | 51.73 |
| 2014 | 52.51 |
| 2015 | 49.4 |
| 2016 | 49.58 |
| 2017 | 49.87 |
| 2018 | 48.8 |