| 年度 | 实际值 |
|---|---|
| 1995 | 63.9 |
| 1996 | 59.2 |
| 1997 | 65.49 |
| 1998 | 50.8 |
| 1999 | 48.7 |
| 2000 | 50.1 |
| 2001 | 49.96 |
| 2002 | 52.2 |
| 2003 | 55.18 |
| 2004 | 53.77 |
| 2005 | 56.32 |
| 2006 | 55.48 |
| 2007 | 53.31 |
| 2008 | 51.51 |
| 2009 | |
| 2010 | 49.64 |
| 2011 | 49.06 |
| 2012 | 48.93 |
| 2013 | 48 |
| 2014 | 47.65 |
| 2015 | 44.4 |
| 2016 | 43.62 |
| 2017 | 42.89 |
| 2018 | 42.63 |