| 年度 | 实际值 |
|---|---|
| 1995 | 36.2 |
| 1996 | 36.6 |
| 1997 | 34.41 |
| 1998 | 35 |
| 1999 | 37.9 |
| 2000 | 37 |
| 2001 | 40.9 |
| 2002 | 34.47 |
| 2003 | 43.04 |
| 2004 | 43.6 |
| 2005 | 44.12 |
| 2006 | 45.06 |
| 2007 | 46.06 |
| 2008 | 45.92 |
| 2009 | |
| 2010 | 44.15 |
| 2011 | 42.54 |
| 2012 | 42.39 |
| 2013 | 44.23 |
| 2014 | 48.81 |
| 2015 | 50.38 |
| 2016 | 53.09 |
| 2017 | 53.56 |
| 2018 | 54.99 |