| 年度 | 实际值 |
|---|---|
| 1995 | 28.5 |
| 1996 | 30.2 |
| 1997 | 30.72 |
| 1998 | 31.1 |
| 1999 | 31.9 |
| 2000 | 33.3 |
| 2001 | 33.96 |
| 2002 | 34.97 |
| 2003 | 35.27 |
| 2004 | 38.94 |
| 2005 | 37.71 |
| 2006 | 37.85 |
| 2007 | 39.42 |
| 2008 | 39.57 |
| 2009 | |
| 2010 | 42.01 |
| 2011 | 41.79 |
| 2012 | 41.45 |
| 2013 | 41.37 |
| 2014 | 43 |
| 2015 | 43.04 |
| 2016 | 43.32 |
| 2017 | |
| 2018 | 45.86 |