| Year | Volume | Number | Holdings | ||
|---|---|---|---|---|---|
| 2010 | - | 25 | Yes | ||
| 2009 | - | 24 | Yes | ||
| 2008 | - | 23 | Yes | ||
| 2007 | - | 22 | Yes | ||
| 2006 | - | 21 | Yes | ||
| 2005 | - | 20 | Yes | ||
| 2004 | - | 19 | Yes | ||
| 2003 | - | 18 | Yes | ||
| 2002 | - | 17 | Yes | ||
| 2000/2001 | - | 15 /16 | Yes | ||
| 1999 | - | 14 | Yes | ||
| 1998 | - | 13 | Yes | ||
| 1997 | - | 12 | Yes | ||
| 1996 | - | 11 | Yes | ||
| 1995 | - | 10 | Yes | ||
| 1994 | - | 9 | Yes | ||
| 1993 | - | 8 | Yes |