| 年度 | 实际值 |
|---|---|
| 1995 | 33.3 |
| 1996 | 34.8 |
| 1997 | 24.86 |
| 1998 | 40.9 |
| 1999 | 42.1 |
| 2000 | 42.7 |
| 2001 | 44.04 |
| 2002 | 43.9 |
| 2003 | 40.14 |
| 2004 | 39.44 |
| 2005 | 47.43 |
| 2006 | 47.58 |
| 2007 | 45.18 |
| 2008 | 43.46 |
| 2009 | |
| 2010 | 47.11 |
| 2011 | 37.95 |
| 2012 | 41.57 |
| 2013 | 44.29 |
| 2014 | 49.03 |
| 2015 | 49.16 |
| 2016 | 49.07 |
| 2017 | |
| 2018 | 52.16 |