| Description | Coverage: 1979-1985, Feb, May + Nov 1991, Jun 1993, Nov 1999, March + Dec 2000, Mar, Jun, Oct + Dec 2001, Mar, Jul, Oct + Dec 2002, Apr, Jul, Oct + Dec 2003, Mar, Jul, Oct + Dec 2004, Mar, Jul, Oct + Dec 2005, Mar, Jun, Oct + Dec 2006, Mar, Jul, Oct + Dec 2007, Mar, Jul, Oct + Dec 2008, Mar + Jun 2009. |