Question: when did oldham become part of greater manchester
[{'answer': '1 April 1974', 'provenance': [{'wikipedia_id': '179445', 'title': 'Oldham', 'start_paragraph_id': 32, 'start_character': 345, 'end_paragraph_id': 32, 'end_character': 357, 'bleu_score': 1.0, 'section': 'Section::::Governance.:Civic history.\n'}]}, {'provenance': [{'wikipedia_id': '179445', 'title': 'Oldham', 'start_paragraph_id': 32, 'start_character': 0, 'end_paragraph_id': 32, 'end_character': 462, 'bleu_score': 0.97451705556073, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10803366432074481612}, 'section': 'Section::::Governance.:Civic history.\n'}]}]