Question: when did swedish become the official language of sweden
[{'answer': '20th century', 'provenance': [{'wikipedia_id': '7873815', 'title': 'Languages of Sweden', 'start_paragraph_id': 5, 'start_character': 161, 'end_paragraph_id': 5, 'end_character': 173, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '7873815', 'title': 'Languages of Sweden', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 400, 'bleu_score': 0.965203995518735, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10653783519121454981}, 'section': 'Section::::History.\n'}]}]