Question: when did the refugee crisis in europe start
[{'answer': '2015', 'provenance': [{'wikipedia_id': '46415102', 'title': 'European migrant crisis', 'start_paragraph_id': 1, 'start_character': 88, 'end_paragraph_id': 1, 'end_character': 92, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '46415102', 'title': 'European migrant crisis', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 423, 'bleu_score': 0.678935273162067, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1717474610715432614}, 'section': 'Section::::Abstract.'}]}]