Question: when did west ham move to olympic stadium
[{'answer': 'August 2016', 'provenance': [{'wikipedia_id': '2179597', 'title': 'London Stadium', 'start_paragraph_id': 86, 'start_character': 86, 'end_paragraph_id': 86, 'end_character': 97, 'bleu_score': 1.0, 'section': 'Section::::Sports.:Football.\n'}]}, {'provenance': [{'wikipedia_id': '2179597', 'title': 'London Stadium', 'start_paragraph_id': 86, 'start_character': 0, 'end_paragraph_id': 86, 'end_character': 394, 'bleu_score': 0.8965302240036541, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6952002357939637913}, 'section': 'Section::::Sports.:Football.\n'}]}]