| 年度 | 实际值 |
|---|---|
| 1995 | 68.4 |
| 1996 | 66.4 |
| 1997 | 42.1 |
| 1998 | 27.3 |
| 1999 | 48.8 |
| 2000 | 46 |
| 2001 | 45.16 |
| 2002 | 47.9 |
| 2003 | 53.66 |
| 2004 | 64.04 |
| 2005 | 59.87 |
| 2006 | 62.08 |
| 2007 | 60.88 |
| 2008 | 59.31 |
| 2009 | |
| 2010 | 58.82 |
| 2011 | 56.12 |
| 2012 | 54.52 |
| 2013 | 48.16 |
| 2014 | 46.91 |
| 2015 | 44.99 |
| 2016 | 43.86 |
| 2017 | 42.88 |
| 2018 | 42.87 |