Question: when was the first speed camera introduced in the uk
[{'answer': '1991', 'provenance': [{'wikipedia_id': '27217976', 'title': 'Road speed limit enforcement in the United Kingdom', 'start_paragraph_id': 62, 'start_character': 11, 'end_paragraph_id': 62, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::History.:Electronic aids.\n'}]}, {'provenance': [{'wikipedia_id': '27217976', 'title': 'Road speed limit enforcement in the United Kingdom', 'start_paragraph_id': 63, 'start_character': 0, 'end_paragraph_id': 63, 'end_character': 259, 'bleu_score': 0.9529077664391161, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10829166982804260032}, 'section': 'Section::::History.:1991 – March 2007 Speed cameras.\n'}]}]