1977 bk. 1 January 20 to June 24, 1977 -- 1977 bk. 2 June 25 to December 31, 1977 -- 1978 bk. 1 January 1 to June 30, 1978 -- 1978 bk. 2 June 30 to December 31, 1978 -- 1979 bk. 1 January 1 to June 22, 1979 -- 1979 bk. 2 June 23 to December 31, 1979 -- 1980/81 bk. 1 January 1 to May 23, 1980 -- 1980/81 bk. 2 May 24 to September 26, 1980 -- 1980/81 bk. 3 September 29, 1980 to January 20, 1981.