| 年度 | 实际值 |
|---|---|
| 1995 | 43.5 |
| 1996 | 48.9 |
| 1997 | 38.58 |
| 1998 | 50.7 |
| 1999 | 51.7 |
| 2000 | 51.9 |
| 2001 | 51.13 |
| 2002 | 49.77 |
| 2003 | 45.93 |
| 2004 | 44.85 |
| 2005 | 51.81 |
| 2006 | 50.98 |
| 2007 | 49.81 |
| 2008 | 47.61 |
| 2009 | |
| 2010 | 37.8 |
| 2011 | 36.02 |
| 2012 | 35.81 |
| 2013 | 35.15 |
| 2014 | 36.97 |
| 2015 | 42.62 |
| 2016 | 57.41 |
| 2017 | 60.13 |
| 2018 | 61.06 |