| 年度 | 实际值 |
|---|---|
| 1995 | 28.9 |
| 1996 | 29.9 |
| 1997 | 31.7 |
| 1998 | 31.8 |
| 1999 | 32.7 |
| 2000 | 33.9 |
| 2001 | 35.57 |
| 2002 | 36.54 |
| 2003 | 37.13 |
| 2004 | 37.02 |
| 2005 | 40.69 |
| 2006 | 40.58 |
| 2007 | 40.53 |
| 2008 | 40.98 |
| 2009 | |
| 2010 | 43.41 |
| 2011 | 44.2 |
| 2012 | 45.43 |
| 2013 | 46.4 |
| 2014 | 48.67 |
| 2015 | 50.32 |
| 2016 | 51.38 |
| 2017 | |
| 2018 | 54.12 |