Question: when was the bridge over the hoover dam built
[{'answer': '2010', 'provenance': [{'wikipedia_id': '1865578', 'title': "Mike O'Callaghan–Pat Tillman Memorial Bridge", 'start_paragraph_id': 1, 'start_character': 345, 'end_paragraph_id': 1, 'end_character': 349, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1865578', 'title': "Mike O'Callaghan–Pat Tillman Memorial Bridge", 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15676729917748077809}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1865578', 'title': "Mike O'Callaghan–Pat Tillman Memorial Bridge", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 809, 'bleu_score': 0.9098586429561001, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15676729917748077809}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '14308', 'title': 'Hoover Dam', 'section': 'Section::::Background.:Search for resources.\n', 'start_paragraph_id': 6, 'end_paragraph_id': 6, 'meta': {'evidence_span': ["Arizona, and California. Hoover Dam is a major tourist attraction; nearly a million people tour the dam each year. The heavily traveled U.S. Route 93 (US\xa093) ran along the dam's crest until October 2010, when the Hoover Dam Bypass opened. As the United States developed the Southwest, the Colorado River was seen as a potential source of irrigation water.", "Arizona, and California. Hoover Dam is a major tourist attraction; nearly a million people tour the dam each year. The heavily traveled U.S. Route 93 (US\xa093) ran along the dam's crest until October 2010, when the Hoover Dam Bypass opened.", '2010, when the Hoover Dam Bypass opened.']}}]}, {'provenance': [{'wikipedia_id': '1865578', 'title': "Mike O'CallaghanPat Tillman Memorial Bridge", 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ["The Mike O'CallaghanPat Tillman Memorial Bridge is an arch bridge in the United States that spans the Colorado River between the states of Arizona and Nevada. The bridge is located within the Lake Mead National Recreation Area approximately southeast of Las Vegas, and carries Interstate 11 and U.S. Route 93 over the Colorado River. Opened in 2010,", 'Opened in 2010, it was the key component of the Hoover Dam Bypass project,']}}]}, {'provenance': [{'wikipedia_id': '14308', 'title': 'Hoover Dam', 'section': 'Section::::Operation.:Roadway and tourism.\n', 'start_paragraph_id': 68, 'end_paragraph_id': 68, 'meta': {'evidence_span': ["The four-lane Hoover Dam Bypass opened on October 19, 2010. It includes a composite steel and concrete arch bridge, the Mike O'CallaghanPat Tillman Memorial Bridge, downstream from the dam. With the opening of the bypass, through traffic is no longer allowed across Hoover Dam; dam visitors are allowed to use the existing roadway to approach from the Nevada side and cross to parking lots and other facilities on the Arizona side. Hoover Dam opened for", 'The four-lane Hoover Dam Bypass opened on October 19, 2010.']}}]}]