| 年度 | 实际值 |
|---|---|
| 1995 | 49.8 |
| 1996 | 50.3 |
| 1997 | 45.02 |
| 1998 | 49.9 |
| 1999 | 44.9 |
| 2000 | 48.9 |
| 2001 | 50.35 |
| 2002 | 51.99 |
| 2003 | 54.49 |
| 2004 | 55.71 |
| 2005 | 57.17 |
| 2006 | 57.28 |
| 2007 | 60.67 |
| 2008 | 61.82 |
| 2009 | |
| 2010 | 61.82 |
| 2011 | 54.46 |
| 2012 | 54.55 |
| 2013 | 54.34 |
| 2014 | 49.6 |
| 2015 | 48.49 |
| 2016 | 46.87 |
| 2017 | 47.52 |
| 2018 | 46.56 |