| 年度 | 实际值 |
|---|---|
| 1995 | 47.5 |
| 1996 | 45 |
| 1997 | 37.73 |
| 1998 | 46.6 |
| 1999 | 47.1 |
| 2000 | 39.7 |
| 2001 | 39.97 |
| 2002 | 38.89 |
| 2003 | 35.96 |
| 2004 | 34.94 |
| 2005 | 34.18 |
| 2006 | 32.65 |
| 2007 | 33.12 |
| 2008 | 31.09 |
| 2009 | |
| 2010 | 33.29 |
| 2011 | 32.44 |
| 2012 | 31.33 |
| 2013 | 33.35 |
| 2014 | 55.93 |
| 2015 | 57.44 |
| 2016 | 62.05 |
| 2017 | 64.1 |
| 2018 | 63.57 |