are all of the dates listed in the date column in 1967?
february 1, 1967, may 17, 1967, may 22, 1967, may 24, 1967, may 30, 1967, june 29, 1967, july 3, 1967, august 16, 1967, september 20, 1967, october 25, 1967, december 20, 1967
which director's name appears the fewest times in the director column?
george singer