| 年度 | 实际值 |
|---|---|
| 1995 | 30.1 |
| 1996 | 29.2 |
| 1997 | 33.67 |
| 1998 | 36.8 |
| 1999 | 42.4 |
| 2000 | 41.5 |
| 2001 | 42.45 |
| 2002 | 39.58 |
| 2003 | 36.23 |
| 2004 | 34.25 |
| 2005 | 40.22 |
| 2006 | 41.84 |
| 2007 | 41.87 |
| 2008 | 41.74 |
| 2009 | |
| 2010 | 46.1 |
| 2011 | 43.76 |
| 2012 | 43.96 |
| 2013 | 47.25 |
| 2014 | 49.83 |
| 2015 | 52.85 |
| 2016 | 57.65 |
| 2017 | |
| 2018 | 58.4 |