| 年度 | 实际值 |
|---|---|
| 1995 | 52.5 |
| 1996 | 50.6 |
| 1997 | 44.88 |
| 1998 | 46.6 |
| 1999 | 47.8 |
| 2000 | 48.7 |
| 2001 | 49.55 |
| 2002 | 47.65 |
| 2003 | 49.74 |
| 2004 | 50.6 |
| 2005 | 53.35 |
| 2006 | 55.26 |
| 2007 | 54.95 |
| 2008 | 56.54 |
| 2009 | |
| 2010 | 56.11 |
| 2011 | 58.37 |
| 2012 | 58.21 |
| 2013 | 56.56 |
| 2014 | 57.7 |
| 2015 | 57.35 |
| 2016 | 56.07 |
| 2017 | |
| 2018 | 52.62 |