| 年度 | 实际值 |
|---|---|
| 1995 | 35.6 |
| 1996 | 36.2 |
| 1997 | 37.48 |
| 1998 | 39.3 |
| 1999 | 43.1 |
| 2000 | 43.4 |
| 2001 | 43.7 |
| 2002 | 43.65 |
| 2003 | 39.89 |
| 2004 | 36.8 |
| 2005 | 39.08 |
| 2006 | 39.27 |
| 2007 | 39.85 |
| 2008 | 39.53 |
| 2009 | |
| 2010 | 41.21 |
| 2011 | 39.69 |
| 2012 | 40.43 |
| 2013 | 39.56 |
| 2014 | 39.58 |
| 2015 | 42.12 |
| 2016 | 44.53 |
| 2017 | |
| 2018 | 51.51 |