Question: when was the basket installed at wrigley field
[{'answer': 'start of the 1970 season', 'provenance': [{'wikipedia_id': '21151238', 'title': 'History of Wrigley Field', 'start_paragraph_id': 50, 'start_character': 109, 'end_paragraph_id': 50, 'end_character': 133, 'bleu_score': 1.0, 'section': 'Section::::"Beautiful Wrigley Field" (1932–1981).:Construction of the bleachers (1937).\n'}]}, {'provenance': [{'wikipedia_id': '21151238', 'title': 'History of Wrigley Field', 'start_paragraph_id': 50, 'start_character': 0, 'end_paragraph_id': 50, 'end_character': 1094, 'bleu_score': 0.9895009487746611, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13281586398482486437}, 'section': 'Section::::"Beautiful Wrigley Field" (1932–1981).:Construction of the bleachers (1937).\n'}]}]