| 年度 | 实际值 |
|---|---|
| 1995 | 49.9 |
| 1996 | 49.9 |
| 1997 | 29.83 |
| 1998 | 52.6 |
| 1999 | 53.7 |
| 2000 | 61.5 |
| 2001 | 58.03 |
| 2002 | 57.97 |
| 2003 | 59 |
| 2004 | 58.58 |
| 2005 | 56.72 |
| 2006 | 49.65 |
| 2007 | 46.61 |
| 2008 | 41.98 |
| 2009 | |
| 2010 | 42.41 |
| 2011 | 38.53 |
| 2012 | 37.72 |
| 2013 | 38.58 |
| 2014 | 38.24 |
| 2015 | 41.21 |
| 2016 | 43.15 |
| 2017 | 51.91 |
| 2018 | 56.45 |