| 年度 | 实际值 |
|---|---|
| 1992 | 255 |
| 1993 | 259 |
| 1994 | 260 |
| 1995 | 262 |
| 1996 | 266 |
| 1997 | 268 |
| 1998 | 271 |
| 1999 | 271 |
| 2000 | 274 |
| 2001 | 277 |
| 2002 | 280 |
| 2003 | 282.15 |
| 2004 | 286.47 |
| 2005 | 286.95 |
| 2006 | 292.28 |
| 2007 | 276.13 |
| 2008 | 301.05 |
| 2009 | |
| 2010 | 310.43 |
| 2011 | 313.15 |
| 2012 | 316.84 |
| 2013 | 316.06 |
| 2014 | 319.03 |
| 2015 | 317.43 |