| 年度 | 实际值 |
|---|---|
| 1995 | 48.7 |
| 1996 | 50.2 |
| 1997 | 52.02 |
| 1998 | 52.6 |
| 1999 | 52.6 |
| 2000 | 49.7 |
| 2001 | 49.97 |
| 2002 | 50.3 |
| 2003 | 51.57 |
| 2004 | 51.55 |
| 2005 | 48.4 |
| 2006 | 49.97 |
| 2007 | 54.64 |
| 2008 | 56.01 |
| 2009 | |
| 2010 | 57.36 |
| 2011 | 59.95 |
| 2012 | 61.52 |
| 2013 | 63.15 |
| 2014 | 61.67 |
| 2015 | 59.6 |
| 2016 | 55.73 |
| 2017 | |
| 2018 | 52.17 |