Question: when was the charter of rights and freedoms signed
[{'answer': 'April 17 , 1982', 'provenance': [{'wikipedia_id': '129190', 'title': 'Canadian Charter of Rights and Freedoms', 'start_paragraph_id': 1, 'start_character': 538, 'end_paragraph_id': 1, 'end_character': 553, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '129190', 'title': 'Canadian Charter of Rights and Freedoms', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 584, 'bleu_score': 0.894790774231468, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1547918021258926610}, 'section': 'Section::::Abstract.'}]}]