| 年度 | 实际值 |
|---|---|
| 1995 | 22.8 |
| 1996 | 23.8 |
| 1997 | 25.18 |
| 1998 | 26.5 |
| 1999 | 26.9 |
| 2000 | 30.4 |
| 2001 | 31.22 |
| 2002 | 31.59 |
| 2003 | 30.71 |
| 2004 | 29.92 |
| 2005 | 29.75 |
| 2006 | 28.1 |
| 2007 | 27.91 |
| 2008 | 28.39 |
| 2009 | |
| 2010 | 33.7 |
| 2011 | 32.65 |
| 2012 | 31.92 |
| 2013 | 34.44 |
| 2014 | 34.76 |
| 2015 | 36.53 |
| 2016 | 38.46 |
| 2017 | |
| 2018 | 43.99 |