| 年度 | 实际值 |
|---|---|
| 1995 | 49.8 |
| 1996 | 49.1 |
| 1997 | 41.29 |
| 1998 | 40.4 |
| 1999 | 38.6 |
| 2000 | 41.6 |
| 2001 | 41.91 |
| 2002 | 44.22 |
| 2003 | 48.94 |
| 2004 | 50.18 |
| 2005 | 51.53 |
| 2006 | 52.43 |
| 2007 | 53.47 |
| 2008 | 54.89 |
| 2009 | |
| 2010 | 57.69 |
| 2011 | 59.13 |
| 2012 | 57.15 |
| 2013 | 56.59 |
| 2014 | 56.6 |
| 2015 | 49.76 |
| 2016 | 49.56 |
| 2017 | |
| 2018 | 47.85 |