| 年度 | 实际值 |
|---|---|
| 1992 | 21.91 |
| 1993 | 23.4 |
| 1994 | 24.37 |
| 1995 | 47.93 |
| 1996 | 48.69 |
| 1997 | 49.24 |
| 1998 | 49.7 |
| 1999 | 50.5 |
| 2000 | 49.5 |
| 2001 | 52.39 |
| 2002 | 52.9 |
| 2003 | 53.93 |
| 2004 | 54.96 |
| 2005 | 55.79 |
| 2006 | 56.92 |
| 2007 | 58.14 |
| 2008 | 59.31 |
| 2009 | |
| 2010 | 60.42 |
| 2011 | 62.6 |
| 2012 | 62.6 |
| 2013 | 63.6 |
| 2014 | 63.7 |
| 2015 | 64.87 |
| 2016 | 66 |
| 2017 | 67 |
| 2018 | 69 |