| 年度 | 实际值 |
|---|---|
| 1993 | 52.12 |
| 1994 | 52.82 |
| 1995 | 53.81 |
| 1996 | 45.61 |
| 1997 | 46.09 |
| 1998 | 46.44 |
| 1999 | 46.68 |
| 2000 | 46.7 |
| 2001 | 47.23 |
| 2002 | 47.44 |
| 2003 | 47.44 |
| 2004 | 48.16 |
| 2005 | 48.71 |
| 2006 | 49.13 |
| 2007 | 49.85 |
| 2008 | 50.74 |
| 2009 | |
| 2010 | 51.86 |
| 2011 | 54.2 |
| 2012 | 54.4 |
| 2013 | 55.3 |
| 2014 | 55.9 |
| 2015 | 56.75 |
| 2016 | 58 |
| 2017 | 58 |
| 2018 | 59 |