Question: when did the 12 valve cummins come out
[{'answer': '1984', 'provenance': [{'wikipedia_id': '1605981', 'title': 'Cummins B Series engine', 'start_paragraph_id': 1, 'start_character': 114, 'end_paragraph_id': 1, 'end_character': 118, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1605981', 'title': 'Cummins B Series engine', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 443, 'bleu_score': 0.646516671463501, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15275582436313714160}, 'section': 'Section::::First generation.:6BT.\n'}]}]