Question: when did iced coffee become popular in the us
[{'answer': '1920', 'provenance': [{'wikipedia_id': '1646753', 'title': 'Iced coffee', 'start_paragraph_id': 7, 'start_character': 122, 'end_paragraph_id': 7, 'end_character': 126, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '1646753', 'title': 'Iced coffee', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 205, 'bleu_score': 0.8592899528284991, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1041586407110235092}, 'section': 'Section::::History.\n'}]}]