Question: when did the uk stop using half pennies
[{'answer': 'December 1984', 'provenance': [{'wikipedia_id': '200125', 'title': 'Halfpenny (British decimal coin)', 'start_paragraph_id': 3, 'start_character': 534, 'end_paragraph_id': 3, 'end_character': 547, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '200125', 'title': 'Halfpenny (British decimal coin)', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 547, 'bleu_score': 0.9792717993254391, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 959406944585011353}, 'section': 'Section::::Abstract.'}]}]