| 年度 | 实际值 |
|---|---|
| 1993 | 6.1 |
| 1994 | |
| 1995 | 23.2 |
| 1996 | 23.5 |
| 1997 | 22.4 |
| 1998 | 23.6 |
| 1999 | 23 |
| 2000 | 24.3 |
| 2001 | 1.6 |
| 2002 | |
| 2003 | 32.23 |
| 2004 | 34.55 |
| 2005 | 37 |
| 2006 | 36.52 |
| 2007 | 37.55 |
| 2008 | 38.59 |
| 2009 | |
| 2010 | 38.95 |
| 2011 | 40.67 |
| 2012 | 37.78 |
| 2013 | 39.3 |
| 2014 | 41.51 |
| 2015 | 40.68 |
| 2016 | 41.15 |
| 2017 | 42.97 |
| 2018 | 43.18 |