Question: when was the decimal currency system introduced in india
[{'answer': '1 April 1957', 'provenance': [{'wikipedia_id': '211017', 'title': 'Decimalisation', 'start_paragraph_id': 80, 'start_character': 70, 'end_paragraph_id': 80, 'end_character': 82, 'bleu_score': 1.0, 'section': 'Section::::Asia.\n'}]}, {'provenance': [{'wikipedia_id': '211017', 'title': 'Decimalisation', 'start_paragraph_id': 80, 'start_character': 0, 'end_paragraph_id': 80, 'end_character': 82, 'bleu_score': 0.8702397637697911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8874147033909452091}, 'section': 'Section::::Asia.\n'}]}]