Question: when did tim hortons open in the usa
[{'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': 2255223324396715550}, 'section': 'Section::::Locations.:United States.\n'}]}, {'provenance': [{'wikipedia_id': '180099', 'title': 'Tim Hortons', 'section': 'Section::::Locations.:United States.\n', 'start_paragraph_id': 42, 'end_paragraph_id': 42, 'meta': {'evidence_span': ['The first United States locations were opened in Deerfield Beach, Florida, and Pompano Beach, Florida, in 1981, but they proved unsuccessful and were closed.', 'Initially, the US stores were the result of natural expansion in CanadaU.S. border areas (e.g., stores in Maine and the Buffalo, New York, area where Horton played from 1972 to 1974 as a member of the Buffalo Sabres). The first United States locations were opened in Deerfield Beach, Florida, and Pompano Beach, Florida, in 1981,', 'Initially, the US stores were the result of natural expansion in CanadaU.S. border areas (e.g., stores in Maine and the Buffalo, New York, area where Horton played from 1972 to 1974 as a member of the Buffalo Sabres). The first United States locations were opened in Deerfield Beach, Florida, and Pompano Beach, Florida, in 1981, but they proved unsuccessful and were closed. In 1985, the chain returned to the US with a location on Niagara Falls Boulevard in the Buffalo suburb of Tonawanda, New York. Starting in the mid-1990s, however, the chain began expanding in the US by acquiring former locations from fast food chains. In 1996 and 1997, thirty-seven former Rax Restaurants locations in Ohio, Kentucky, and West Virginia were bought by Wendy\'s International Inc.; 30 of these were converted to Tim Hortons, while the others became Wendy\'s franchise locations. Thirty-five closed Hardee\'s stores in the Detroit area were also purchased with the intention of being converted. By 2004, the chain had also acquired 42 Bess Eaton coffee and doughnut restaurants situated in southern New England. Several combination Wendy\'s/Tim Hortons units were opened in the US; both in the "traditional" markets of Maine and Buffalo, where there were well over 180 locations as of 2011, and in the markets entered through acquisition.']}}]}]