1978
circa 1976
Stickney, William S.
June 1972
September 21 – December 20 1970
Etter, Alfred G.
December 21 1970 – March 20 1971
March 21 – September 20 1971
September 21 – December 20 1971
December 21 1971 – March 20 1972
March 21 – June 20 1972
June 21 – September 20 1972
September 21 – December 20 1972
March 21 – June 20 1974
September 21 – December 20 1974
September 21 – December 20 1975
December 21 1975 – March 20 1976
June 21 – September 20 1976
December 21 1976 – March 20 1977
March 21 – June 20 1977
June 21 – September 20 1977
March 21 – June 20 1978