Question: when did medicare begin in the united states
[{'answer': '1966', 'provenance': [{'wikipedia_id': '58353', 'title': 'Medicare (United States)', 'start_paragraph_id': 1, 'start_character': 79, 'end_paragraph_id': 1, 'end_character': 83, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]