| 年度 | 实际值 |
|---|---|
| 1995 | 39.6 |
| 1996 | 42.6 |
| 1997 | 45.72 |
| 1998 | 45 |
| 1999 | 45.4 |
| 2000 | 44.6 |
| 2001 | 43.66 |
| 2002 | 44.14 |
| 2003 | 45.18 |
| 2004 | 46.62 |
| 2005 | 41.12 |
| 2006 | 42.27 |
| 2007 | 41.37 |
| 2008 | 42.44 |
| 2009 | |
| 2010 | 53.03 |
| 2011 | 55.33 |
| 2012 | 55.85 |
| 2013 | 53.14 |
| 2014 | 52.76 |
| 2015 | 50.36 |
| 2016 | 47.49 |
| 2017 | |
| 2018 | 49.87 |