Question: when did soccer become popular in the united states
[{'answer': 'the 1960s', 'provenance': [{'wikipedia_id': '579105', 'title': 'Soccer in the United States', 'start_paragraph_id': 2, 'start_character': 257, 'end_paragraph_id': 2, 'end_character': 266, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '579105', 'title': 'Soccer in the United States', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 584, 'bleu_score': 0.658947296090809, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13903341978653206073}, 'section': 'Section::::Abstract.'}]}]