Question: when was dewalt bought by black and decker
[{'answer': '1949', 'provenance': [{'wikipedia_id': '4761325', 'title': 'DeWalt', 'start_paragraph_id': 3, 'start_character': 215, 'end_paragraph_id': 3, 'end_character': 219, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '4761325', 'title': 'DeWalt', 'start_paragraph_id': 3, 'start_character': 187, 'end_paragraph_id': 3, 'end_character': 291, 'bleu_score': 0.8914703664390791, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3447639640985495709}, 'section': 'Section::::History.\n'}]}]