| 年度 | 实际值 |
|---|---|
| 1992 | 68.97 |
| 1993 | 70.23 |
| 1994 | 71.25 |
| 1995 | 72.24 |
| 1996 | 22.22 |
| 1997 | 22.9 |
| 1998 | 23.06 |
| 1999 | 24.81 |
| 2000 | 25.86 |
| 2001 | 26.45 |
| 2002 | 27.17 |
| 2003 | 28.18 |
| 2004 | 29.77 |
| 2005 | 30.41 |
| 2006 | 31.71 |
| 2007 | 32.8 |
| 2008 | 36.74 |
| 2009 | |
| 2010 | 34.3 |
| 2011 | 35.4 |
| 2012 | 36.2 |
| 2013 | 36.8 |
| 2014 | 37.2 |
| 2015 | 37.75 |
| 2016 | 38 |
| 2017 | 39 |
| 2018 | 40 |