[['state (class)', 'vacator', 'reason for change', 'successor', "date of successor 's formal installation"], ['georgia (2)', 'richard russell , jr (d)', 'died january 21 , 1971', 'david h gambrell (d)', 'february 1 , 1971'], ['vermont (1)', 'winston l prouty (r)', 'died september 10 , 1971', 'robert stafford (r)', 'september 16 , 1971'], ['louisiana (2)', 'allen j ellender (d)', 'died july 27 , 1972', 'elaine s edwards (d)', 'august 1 , 1972'], ['georgia (2)', 'david h gambrell (d)', 'successor elected november 7 , 1972', 'sam nunn (d)', 'november 7 , 1972'], ['louisiana (2)', 'elaine s edwards (d)', 'successor elected november 13 , 1972', 'bennett johnston , jr (d)', 'november 14 , 1972']]
Bennett johnson , Jr 's Formal Installation was 1 week after Sam Nunn 's
[ENT] johnson [ENT] [ENT] was 1 week after [ENT] 's