| 年度 | 实际值 |
|---|---|
| 1995 | 47.3 |
| 1996 | 44.9 |
| 1997 | 33.22 |
| 1998 | 40.5 |
| 1999 | |
| 2000 | 41.6 |
| 2001 | 42.4 |
| 2002 | 40.18 |
| 2003 | 40.43 |
| 2004 | 37.64 |
| 2005 | 37.77 |
| 2006 | 37.26 |
| 2007 | 38.45 |
| 2008 | 39.1 |
| 2009 | |
| 2010 | 39.41 |
| 2011 | 36.45 |
| 2012 | 36.91 |
| 2013 | 37.25 |
| 2014 | 41.1 |
| 2015 | 43.19 |
| 2016 | 45.34 |
| 2017 | 45.74 |
| 2018 | 47.72 |