1977 November 3 1977 December 1 1978 May 4 1978 June 29 1979 March 22 1979 May 17 1980 February 21 1982 December 23 1986 December 4 1986 December 18 1987 August 27 1988 December 15 1989 June 1 1989 December 14 1991 May 16 2004 April 15 2005 May 5