| 年度 | 实际值 |
|---|---|
| 1995 | 37.2 |
| 1996 | 37.8 |
| 1997 | 58.58 |
| 1998 | 38.1 |
| 1999 | 40.4 |
| 2000 | 41.4 |
| 2001 | 27.78 |
| 2002 | 27.87 |
| 2003 | 34.42 |
| 2004 | 34.18 |
| 2005 | 33.86 |
| 2006 | 35.61 |
| 2007 | 38.72 |
| 2008 | 40.53 |
| 2009 | |
| 2010 | 46.77 |
| 2011 | 54.07 |
| 2012 | 55.65 |
| 2013 | 55.23 |
| 2014 | 54.17 |
| 2015 | 52.21 |
| 2016 | 51.56 |
| 2017 | 47.4 |
| 2018 | 45.57 |