| 年度 | 实际值 |
|---|---|
| 1995 | 52.9 |
| 1996 | 44.6 |
| 1997 | 40.55 |
| 1998 | 43 |
| 1999 | 43.8 |
| 2000 | 44.6 |
| 2001 | 46.9 |
| 2002 | 49.41 |
| 2003 | 52.96 |
| 2004 | 56.14 |
| 2005 | 56.71 |
| 2006 | 59.62 |
| 2007 | 64.22 |
| 2008 | 65.07 |
| 2009 | |
| 2010 | 57.54 |
| 2011 | 67.48 |
| 2012 | 63.89 |
| 2013 | 58.27 |
| 2014 | 58.16 |
| 2015 | 56.4 |
| 2016 | 54.05 |
| 2017 | 52.82 |
| 2018 | 51.89 |