| 年度 | 实际值 |
|---|---|
| 1992 | 23.1 |
| 1993 | 24.3 |
| 1994 | 24.5 |
| 1995 | 29 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 58.9 |
| 2000 | 64.3 |
| 2001 | 71.2 |
| 2002 | 73.1933664368703 |
| 2003 | 76.3443244074547 |
| 2004 | 78.2220701535915 |
| 2005 | 83.07 |
| 2006 | 74.93 |
| 2007 | 81.1275490195999 |
| 2008 | 81.5922361315122 |
| 2009 | 85.84 |
| 2010 | 64.6004274214087 |
| 2011 | 54.52 |
| 2012 | 68.15 |
| 2013 | 57.55 |
| 2014 | 56.64 |
| 2015 | 49.990851753529 |