Question: when did mandela write long walk to freedom
[{'answer': '1994', 'provenance': [{'wikipedia_id': '2108345', 'title': 'Long Walk to Freedom', 'start_paragraph_id': 1, 'start_character': 115, 'end_paragraph_id': 1, 'end_character': 119, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2108345', 'title': 'Long Walk to Freedom', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 660, 'bleu_score': 0.9813933169956551, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7097615042904956355}, 'section': 'Section::::Abstract.'}]}]