| 年度 | 实际值 |
|---|---|
| 1995 | 41.6 |
| 1996 | 42.8 |
| 1997 | 46 |
| 1998 | 38.2 |
| 1999 | 36.6 |
| 2000 | 36.5 |
| 2001 | 35.17 |
| 2002 | 35.43 |
| 2003 | 35.88 |
| 2004 | 39.28 |
| 2005 | |
| 2006 | 48.36 |
| 2007 | 49.75 |
| 2008 | 53.21 |
| 2009 | |
| 2010 | 51.13 |
| 2011 | 59.25 |
| 2012 | 59.85 |
| 2013 | 67.07 |
| 2014 | 67.96 |
| 2015 | 59.28 |
| 2016 | 57.61 |
| 2017 | 56.68 |
| 2018 | 39.97 |