| 年度 | 实际值 |
|---|---|
| 1995 | 33.5 |
| 1996 | 33.5 |
| 1997 | 19.1 |
| 1998 | 38.3 |
| 1999 | 39.5 |
| 2000 | 44.2 |
| 2001 | 45.04 |
| 2002 | 45.38 |
| 2003 | 45.88 |
| 2004 | 43.36 |
| 2005 | 51.5 |
| 2006 | 50.4 |
| 2007 | 52.59 |
| 2008 | 52.05 |
| 2009 | |
| 2010 | 52.36 |
| 2011 | 53.01 |
| 2012 | 50.61 |
| 2013 | 53.46 |
| 2014 | 61.25 |
| 2015 | 64.15 |
| 2016 | 66.38 |
| 2017 | 66.84 |
| 2018 | 67.96 |