Question: when was the pink flamingo lawn ornament invented
[{'answer': '1957', 'provenance': [{'wikipedia_id': '6270484', 'title': 'Don Featherstone (artist)', 'start_paragraph_id': 1, 'start_character': 110, 'end_paragraph_id': 1, 'end_character': 114, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6270484', 'title': 'Don Featherstone (artist)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 354, 'bleu_score': 0.9645876452711911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17286589891961545252}, 'section': 'Section::::Abstract.'}]}]