| 年度 | 实际值 |
|---|---|
| 1995 | 28.6 |
| 1996 | 35.5 |
| 1997 | 26.98 |
| 1998 | 39 |
| 1999 | 40.3 |
| 2000 | 40.5 |
| 2001 | 42.39 |
| 2002 | 42.92 |
| 2003 | 38.18 |
| 2004 | 37.18 |
| 2005 | 41.24 |
| 2006 | 40.7 |
| 2007 | 39 |
| 2008 | 37.53 |
| 2009 | |
| 2010 | 42.86 |
| 2011 | 40.04 |
| 2012 | 42.15 |
| 2013 | 43.17 |
| 2014 | 46.77 |
| 2015 | 50.05 |
| 2016 | 49.4 |
| 2017 | 48.51 |
| 2018 | 48.66 |