Question: when was the decimal system of currency introduced in india
[{'answer': '1 April 1957', 'provenance': [{'wikipedia_id': '1467510', 'title': 'Coins of the Indian rupee', 'start_paragraph_id': 19, 'start_character': 232, 'end_paragraph_id': 19, 'end_character': 244, 'bleu_score': 1.0, 'section': 'Section::::Coin series: 1947-1957 (pre-decimalization).:Decimalization.\n'}]}, {'provenance': [{'wikipedia_id': '1467510', 'title': 'Coins of the Indian rupee', 'start_paragraph_id': 19, 'start_character': 0, 'end_paragraph_id': 19, 'end_character': 543, 'bleu_score': 0.978375183951072, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15236738332116543964}, 'section': 'Section::::Coin series: 1947-1957 (pre-decimalization).:Decimalization.\n'}]}]