| 年度 | 实际值 |
|---|---|
| 1995 | 54.8 |
| 1996 | 56.7 |
| 1997 | 26.56 |
| 1998 | 39.2 |
| 1999 | 38.9 |
| 2000 | 38.3 |
| 2001 | 38.3 |
| 2002 | 38.08 |
| 2003 | 40.71 |
| 2004 | 34.28 |
| 2005 | 35.68 |
| 2006 | 37.88 |
| 2007 | 38.73 |
| 2008 | 38 |
| 2009 | |
| 2010 | 33.49 |
| 2011 | 31.63 |
| 2012 | 33.62 |
| 2013 | 35.67 |
| 2014 | 39.9 |
| 2015 | 40.78 |
| 2016 | 40.95 |
| 2017 | 42.02 |
| 2018 | 43.44 |