Question: when did tolkien begin writing the lord of the rings
[{'answer': 'between 1937 and 1949', 'provenance': [{'wikipedia_id': '29798', 'title': 'The Lord of the Rings', 'start_paragraph_id': 1, 'start_character': 250, 'end_paragraph_id': 1, 'end_character': 271, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '29798', 'title': 'The Lord of the Rings', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 378, 'bleu_score': 0.9338603241255111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9318656471066164375}, 'section': 'Section::::Abstract.'}]}]