| 年度 | 实际值 |
|---|---|
| 1995 | 37.7 |
| 1996 | 35.5 |
| 1997 | 31.75 |
| 1998 | 31.9 |
| 1999 | 34.9 |
| 2000 | 33 |
| 2001 | 32.91 |
| 2002 | 33.34 |
| 2003 | 30.6 |
| 2004 | 28.42 |
| 2005 | 52.32 |
| 2006 | 55.33 |
| 2007 | 48.22 |
| 2008 | 47.5 |
| 2009 | |
| 2010 | 49.55 |
| 2011 | 48.85 |
| 2012 | 47.69 |
| 2013 | 48.23 |
| 2014 | 51.24 |
| 2015 | 55.73 |
| 2016 | 58.33 |
| 2017 | 61.19 |
| 2018 | 61.62 |