| 年度 | 实际值 |
|---|---|
| 1995 | 39.6 |
| 1996 | 37.5 |
| 1997 | 32.38 |
| 1998 | 39.3 |
| 1999 | 38.8 |
| 2000 | 39.3 |
| 2001 | 41.35 |
| 2002 | 42.3 |
| 2003 | 40.93 |
| 2004 | 41.65 |
| 2005 | 49.12 |
| 2006 | 48.93 |
| 2007 | 48.89 |
| 2008 | 47.16 |
| 2009 | |
| 2010 | 50.12 |
| 2011 | 47.89 |
| 2012 | 48.24 |
| 2013 | 48.32 |
| 2014 | 50.86 |
| 2015 | 51.71 |
| 2016 | 51.41 |
| 2017 | 58.13 |
| 2018 | 59.4 |