Question: when did croatia become part of the eu
[{'answer': '1 July 2013', 'provenance': [{'wikipedia_id': '4638190', 'title': '2013 enlargement of the European Union', 'start_paragraph_id': 1, 'start_character': 107, 'end_paragraph_id': 1, 'end_character': 118, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4638190', 'title': '2013 enlargement of the European Union', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 118, 'bleu_score': 0.910879922930628, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7709217736112651415}, 'section': 'Section::::Abstract.'}]}]