Question: when was facebook first opened to the public
[{'answer': 'September 26 , 2006', 'provenance': [{'wikipedia_id': '27951979', 'title': 'History of Facebook', 'start_paragraph_id': 13, 'start_character': 701, 'end_paragraph_id': 13, 'end_character': 722, 'bleu_score': 1.0, 'section': 'Section::::FaceMash.\n'}]}, {'provenance': [{'wikipedia_id': '27951979', 'title': 'History of Facebook', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 777, 'bleu_score': 0.96884390413548, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15105664966086523981}, 'section': 'Section::::FaceMash.\n'}]}]