| 年度 | 实际值 |
|---|---|
| 1995 | 32.7 |
| 1996 | 34.7 |
| 1997 | 34.46 |
| 1998 | 36.5 |
| 1999 | 38.8 |
| 2000 | 42.2 |
| 2001 | 43.06 |
| 2002 | 43.91 |
| 2003 | 46.54 |
| 2004 | 44.29 |
| 2005 | 43.31 |
| 2006 | 43.08 |
| 2007 | 41.06 |
| 2008 | 38.26 |
| 2009 | |
| 2010 | 36.71 |
| 2011 | 34.77 |
| 2012 | 35.06 |
| 2013 | 35.78 |
| 2014 | 37.48 |
| 2015 | 39.33 |
| 2016 | 42 |
| 2017 | |
| 2018 | 47.94 |