| 年度 | 实际值 |
|---|---|
| 1995 | 43.6 |
| 1996 | 44.1 |
| 1997 | 45.55 |
| 1998 | 42.6 |
| 1999 | 42.3 |
| 2000 | 40.5 |
| 2001 | 41.28 |
| 2002 | 40.83 |
| 2003 | 43.59 |
| 2004 | 40.52 |
| 2005 | 37.97 |
| 2006 | 38.65 |
| 2007 | 41.26 |
| 2008 | 42.86 |
| 2009 | |
| 2010 | 49.16 |
| 2011 | 51.69 |
| 2012 | 52.29 |
| 2013 | 53 |
| 2014 | 53.62 |
| 2015 | 53.22 |
| 2016 | 49.71 |
| 2017 | |
| 2018 | 51.62 |