| 年度 | 实际值 |
|---|---|
| 1995 | 48.9 |
| 1996 | 50.8 |
| 1997 | 38.54 |
| 1998 | 52.1 |
| 1999 | 51.6 |
| 2000 | 51.4 |
| 2001 | 51.42 |
| 2002 | 51.19 |
| 2003 | 49.39 |
| 2004 | 48.05 |
| 2005 | 52.54 |
| 2006 | 49.87 |
| 2007 | 47.39 |
| 2008 | 46.62 |
| 2009 | |
| 2010 | 50.97 |
| 2011 | 50.35 |
| 2012 | 50.73 |
| 2013 | 52.62 |
| 2014 | 44.09 |
| 2015 | 47.06 |
| 2016 | 45.25 |
| 2017 | 58.65 |
| 2018 | 56.8 |