| 年度 | 实际值 |
|---|---|
| 1995 | 39.9 |
| 1996 | 39.6 |
| 1997 | 39.68 |
| 1998 | 41.2 |
| 1999 | 44.1 |
| 2000 | 44.1 |
| 2001 | 44.97 |
| 2002 | 44.53 |
| 2003 | 44.12 |
| 2004 | 44.49 |
| 2005 | 42.69 |
| 2006 | 41.04 |
| 2007 | 40.59 |
| 2008 | 39.2 |
| 2009 | |
| 2010 | 35.07 |
| 2011 | 35.04 |
| 2012 | 36.13 |
| 2013 | 37.22 |
| 2014 | 40.93 |
| 2015 | 43.18 |
| 2016 | 52.22 |
| 2017 | |
| 2018 | 52.75 |