| 年度 | 实际值 |
|---|---|
| 1995 | 35.3 |
| 1996 | 31.6 |
| 1997 | 39.97 |
| 1998 | 43.5 |
| 1999 | 47.2 |
| 2000 | 43.1 |
| 2001 | 43.32 |
| 2002 | 45.99 |
| 2003 | 45.27 |
| 2004 | 44.45 |
| 2005 | 49.29 |
| 2006 | 49.85 |
| 2007 | 49.62 |
| 2008 | 47.78 |
| 2009 | |
| 2010 | 44.35 |
| 2011 | 42.67 |
| 2012 | 37.72 |
| 2013 | 42.78 |
| 2014 | 46.68 |
| 2015 | 47.11 |
| 2016 | 47.61 |
| 2017 | |
| 2018 | 53.14 |