| 年度 | 实际值 |
|---|---|
| 1995 | 41.6 |
| 1996 | 40.2 |
| 1997 | 42.49 |
| 1998 | 42.7 |
| 1999 | 41.7 |
| 2000 | 43 |
| 2001 | 42.92 |
| 2002 | 40.73 |
| 2003 | 39.06 |
| 2004 | 38.42 |
| 2005 | 43.05 |
| 2006 | 44.53 |
| 2007 | 45.57 |
| 2008 | 46.18 |
| 2009 | |
| 2010 | 49.15 |
| 2011 | 47.95 |
| 2012 | 50.33 |
| 2013 | 51.6 |
| 2014 | 54.67 |
| 2015 | 55.71 |
| 2016 | 58.57 |
| 2017 | |
| 2018 | 58.16 |