Question: when did the karner blue butterfly become endangered
[{'answer': '1992', 'provenance': [{'wikipedia_id': '2145377', 'title': 'Karner blue', 'start_paragraph_id': 1, 'start_character': 559, 'end_paragraph_id': 1, 'end_character': 563, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2145377', 'title': 'Karner blue', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 776, 'bleu_score': 0.9085630273657721, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5061191778731858814}, 'section': 'Section::::Abstract.'}]}]