Date
- 1988-10-01T07:00:00Z1
- 1989-05-01T07:00:00Z1
- 1990-05-01T07:00:00Z1
- 1991-05-01T07:00:00Z1
- 1992-05-01T07:00:00Z1
- 1993-05-01T07:00:00Z1
- 1994-05-01T07:00:00Z1
- 1995-05-01T07:00:00Z1
- 1996-05-01T07:00:00Z1
- 1997-05-01T07:00:00Z1
- 1998-05-01T07:00:00Z1
- 1999-05-01T07:00:00Z1
- 2000-05-01T07:00:00Z1
- 2001-05-01T07:00:00Z1
- 2002-05-01T07:00:00Z1
- 2003-05-01T07:00:00Z1
- 2004-05-01T07:00:00Z1
- 2005-05-01T07:00:00Z1
- 2006-05-01T07:00:00Z1
- 2007-05-01T07:00:00Z1