1977 October 22 1977 November 26 1978 January 14 1981 January 24 1979 March 3 1979 March 24 1982 August 14 1982 September 11 1986 October 18 1986 November 15 1987 November 14 1994 February 5 1996 May 18 1996 June 8 1996 December 21 1997 October 25 1998 February 7 2005 August 20 2006 June 3