Question: what year did the polaroid 600 come out
[{'answer': '1978', 'provenance': [{'wikipedia_id': '3058419', 'title': 'List of Polaroid instant cameras', 'start_paragraph_id': 78, 'start_character': 17, 'end_paragraph_id': 78, 'end_character': 21, 'bleu_score': 1.0, 'section': 'Section::::Pack film (colorpack).\n'}]}]