| 年度 | 实际值 |
|---|---|
| 1995 | 37.5 |
| 1996 | 38.6 |
| 1997 | 43.84 |
| 1998 | 44.9 |
| 1999 | 46.7 |
| 2000 | 32.6 |
| 2001 | 33.91 |
| 2002 | 33.15 |
| 2003 | 32.09 |
| 2004 | 32.39 |
| 2005 | 38.79 |
| 2006 | 39.9 |
| 2007 | 39.94 |
| 2008 | 40.08 |
| 2009 | |
| 2010 | 44.65 |
| 2011 | 45.03 |
| 2012 | 46.06 |
| 2013 | 47.47 |
| 2014 | 48.42 |
| 2015 | 48.72 |
| 2016 | 49.93 |
| 2017 | |
| 2018 | 50.32 |