1977 March 26 1977 May 28 1977 July 16 1977 July 23 1977 August 13 1977 November 26 1977 December 31 1978 January 21 1978 March 4 1978 March 11 1978 March 25 1978 April 22 1978 November 25 1978 December 30 1979 January 6 1979 May 19 1979 October 13 1979 December 15 1980 January 12 1980 February 23 1980 March 8 1980 April 12 1980 May 10 1980 August 23 1980 October 4 1980 December 27 1981 January 10 1981 January 17 1981 January 24 1981 March 14 1981 unknown date 1981 April 4 1981 August 8 1981 September 12 1981 October 24 1981 November 7 1982 January 9 1982 January 16 1982 unknown date 1982 June 26 1982 September 4 1982 October 9 1983 July 30 1983 August 20 1984 May 12 1984 June 30 1985 September 21 1986 February 22 1986 March 8 1986 April 26 1986 May 31 1986 September 20 1986 December 6 1987 December 12 1989 February 11 1989 April 29 1989 July 1 1989 July 29