| 年度 | 实际值 |
|---|---|
| 1995 | 57.8 |
| 1996 | 54.4 |
| 1997 | 56.55 |
| 1998 | 52.9 |
| 1999 | 51.3 |
| 2000 | 52.4 |
| 2001 | 51.37 |
| 2002 | 51.3 |
| 2003 | 55.42 |
| 2004 | 56.94 |
| 2005 | 32.52 |
| 2006 | 35.5 |
| 2007 | 40.2 |
| 2008 | 43.62 |
| 2009 | |
| 2010 | 58.44 |
| 2011 | 62.14 |
| 2012 | 60.3 |
| 2013 | 59.16 |
| 2014 | 45.67 |
| 2015 | 42.02 |
| 2016 | 38.46 |
| 2017 | 45.33 |
| 2018 | 46.45 |