| 年度 | 实际值 |
|---|---|
| 1995 | 32.6 |
| 1996 | 32.3 |
| 1997 | 34.69 |
| 1998 | 37 |
| 1999 | 40.4 |
| 2000 | 43.9 |
| 2001 | 45.47 |
| 2002 | 44.04 |
| 2003 | 46.39 |
| 2004 | 46 |
| 2005 | 54.26 |
| 2006 | 55.51 |
| 2007 | 55.4 |
| 2008 | 55.46 |
| 2009 | |
| 2010 | 54.36 |
| 2011 | 48.72 |
| 2012 | 48.18 |
| 2013 | 49.52 |
| 2014 | 50.45 |
| 2015 | 51.52 |
| 2016 | 52.2 |
| 2017 | 51.15 |
| 2018 | 51.4 |