Question: when did tim hortons open in the us
[{'answer': '1981', 'provenance': [{'wikipedia_id': '180099', 'title': 'Tim Hortons', 'start_paragraph_id': 42, 'start_character': 325, 'end_paragraph_id': 42, 'end_character': 329, 'bleu_score': 1.0, 'section': 'Section::::Locations.:United States.\n'}]}, {'provenance': [{'wikipedia_id': '180099', 'title': 'Tim Hortons', 'start_paragraph_id': 42, 'start_character': 0, 'end_paragraph_id': 42, 'end_character': 1324, 'bleu_score': 0.9637759331192951, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13901682792738009471}, 'section': 'Section::::Locations.:United States.\n'}]}]