user: Question: under which president was Gunther Volz executed?
Columns: ['Executed person', 'Date of execution', 'Place of execution', 'Crime', 'Method', 'Under President']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Jean Dupont', '14 April 1959', 'Paris', 'Child murder with premeditation', 'Guillotine', 'Charles de Gaulle']
SQL:

assistant: SELECT "Under President" FROM "Table" WHERE "Executed person" = 'Gunther Volz';