Question: when did the springbok tour start and end
[{'answer': '1981', 'provenance': [{'wikipedia_id': '255926', 'title': '1981 South Africa rugby union tour of New Zealand and the United States', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 4, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '255926', 'title': '1981 South Africa rugby union tour of New Zealand and the United States', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 325, 'bleu_score': 0.96188712955549, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16340980140011561590}, 'section': 'Section::::Abstract.'}]}]