| 年度 | 实际值 |
|---|---|
| 1995 | 33.2 |
| 1996 | 38.2 |
| 1997 | 31.63 |
| 1998 | 46.2 |
| 1999 | 48.4 |
| 2000 | 47.3 |
| 2001 | 47.73 |
| 2002 | 45.71 |
| 2003 | 43.13 |
| 2004 | 43.68 |
| 2005 | 41.28 |
| 2006 | 42.17 |
| 2007 | 44.88 |
| 2008 | 46.68 |
| 2009 | |
| 2010 | 48.44 |
| 2011 | 49.26 |
| 2012 | 49.41 |
| 2013 | 50.39 |
| 2014 | 50.82 |
| 2015 | 54.22 |
| 2016 | 55.21 |
| 2017 | 56.17 |
| 2018 | 56.54 |