| 年度 | 实际值 |
|---|---|
| 1993 | 15.9 |
| 1994 | |
| 1995 | 18.4 |
| 1996 | 20.6 |
| 1997 | 25.2 |
| 1998 | 25.5 |
| 1999 | 24.6 |
| 2000 | 24.3 |
| 2001 | 1.62 |
| 2002 | |
| 2003 | 28.11 |
| 2004 | 29.75 |
| 2005 | 37 |
| 2006 | 37.61 |
| 2007 | 30.4 |
| 2008 | 24.74 |
| 2009 | |
| 2010 | 39.13 |
| 2011 | 39.82 |
| 2012 | 40.02 |
| 2013 | 40.21 |
| 2014 | 40.4 |
| 2015 | 41.2 |
| 2016 | 41.78 |
| 2017 | 42.2 |
| 2018 | 43 |