| 年度 | 实际值 |
|---|---|
| 1995 | 56.7 |
| 1996 | 65.7 |
| 1997 | 23.75 |
| 1998 | 45.7 |
| 1999 | 41.9 |
| 2000 | 49.3 |
| 2001 | 49.27 |
| 2002 | 47.15 |
| 2003 | 47.19 |
| 2004 | 45.75 |
| 2005 | 39.01 |
| 2006 | 39.9 |
| 2007 | 42.61 |
| 2008 | 43.83 |
| 2009 | |
| 2010 | 45.95 |
| 2011 | 45.33 |
| 2012 | 46.69 |
| 2013 | 47.09 |
| 2014 | 37.15 |
| 2015 | 35.69 |
| 2016 | 35.26 |
| 2017 | 35.17 |
| 2018 | 34.79 |