| 年度 | 实际值 |
|---|---|
| 1993 | 29.5 |
| 1994 | |
| 1995 | 29.8 |
| 1996 | 29.4 |
| 1997 | 29.7 |
| 1998 | 30.5 |
| 1999 | 31.2 |
| 2000 | 31.7 |
| 2001 | 2.12 |
| 2002 | |
| 2003 | 35.21 |
| 2004 | 37.37 |
| 2005 | 39 |
| 2006 | 40.44 |
| 2007 | 41.42 |
| 2008 | 41.95 |
| 2009 | |
| 2010 | 42.09 |
| 2011 | 42.21 |
| 2012 | 42.27 |
| 2013 | 42.8 |
| 2014 | 42.92 |
| 2015 | 43.13 |
| 2016 | 43.13 |
| 2017 | 43.1 |
| 2018 | 43 |