Question: when did the earned income tax credit start
[{'answer': '1975', 'provenance': [{'wikipedia_id': '19283199', 'title': 'Earned income tax credit', 'start_paragraph_id': 6, 'start_character': 11, 'end_paragraph_id': 6, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Overview.\n'}]}, {'provenance': [{'wikipedia_id': '19283199', 'title': 'Earned income tax credit', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 516, 'bleu_score': 0.9470882598755391, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7307750976548785609}, 'section': 'Section::::Overview.\n'}]}]