Question: where has the olympics been held the most
[{'answer': 'London', 'provenance': [{'wikipedia_id': '11015817', 'title': 'List of Olympic Games host cities', 'start_paragraph_id': 1, 'start_character': 558, 'end_paragraph_id': 1, 'end_character': 564, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '11015817', 'title': 'List of Olympic Games host cities', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 1151, 'bleu_score': 0.843646628667387, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9395565996640008904}, 'section': 'Section::::Abstract.'}]}]