| 年度 | 实际值 |
|---|---|
| 1995 | 45.5 |
| 1996 | 43.3 |
| 1997 | 59.84 |
| 1998 | 41.7 |
| 1999 | 42.7 |
| 2000 | 43.5 |
| 2001 | 44.12 |
| 2002 | 44.65 |
| 2003 | 45.78 |
| 2004 | 48.33 |
| 2005 | 43.84 |
| 2006 | 46.72 |
| 2007 | 49.31 |
| 2008 | 50.19 |
| 2009 | |
| 2010 | 46.12 |
| 2011 | 47.47 |
| 2012 | 47.16 |
| 2013 | 45.39 |
| 2014 | 53.5 |
| 2015 | 50.56 |
| 2016 | 49.99 |
| 2017 | 38.42 |
| 2018 | 40.27 |