| 年度 | 实际值 |
|---|---|
| 1995 | 34.2 |
| 1996 | 35.9 |
| 1997 | 40.98 |
| 1998 | 38.4 |
| 1999 | 43.3 |
| 2000 | 47.3 |
| 2001 | 46.46 |
| 2002 | 42.47 |
| 2003 | 38.61 |
| 2004 | 37.1 |
| 2005 | 40.83 |
| 2006 | 41.4 |
| 2007 | 39.56 |
| 2008 | 37.71 |
| 2009 | |
| 2010 | 33.72 |
| 2011 | 32.64 |
| 2012 | 31.92 |
| 2013 | 31.98 |
| 2014 | 35.6 |
| 2015 | 39.28 |
| 2016 | 49.19 |
| 2017 | |
| 2018 | 51.05 |