| 年度 | 实际值 |
|---|---|
| 1995 | 34.7 |
| 1996 | 39.2 |
| 1997 | 38.73 |
| 1998 | 40.1 |
| 1999 | |
| 2000 | 43.6 |
| 2001 | 45.12 |
| 2002 | 44.58 |
| 2003 | 47.97 |
| 2004 | 47.69 |
| 2005 | 41.78 |
| 2006 | 42.09 |
| 2007 | 44.14 |
| 2008 | 39.4 |
| 2009 | |
| 2010 | 48.24 |
| 2011 | 48.59 |
| 2012 | 49.97 |
| 2013 | 51.03 |
| 2014 | 49.87 |
| 2015 | 49.05 |
| 2016 | 47.65 |
| 2017 | 47.84 |
| 2018 | 49.18 |