Question: sbestos is commonly found in buildings and structures built before what year
[{'answer': 'before the late 1990s', 'provenance': [{'wikipedia_id': '21492663', 'title': 'Asbestos', 'start_paragraph_id': 67, 'start_character': 405, 'end_paragraph_id': 67, 'end_character': 426, 'bleu_score': 1.0, 'section': 'Section::::History.:Construction.:Developed countries.\n'}]}, {'provenance': [{'wikipedia_id': '21492663', 'title': 'Asbestos', 'start_paragraph_id': 67, 'start_character': 0, 'end_paragraph_id': 67, 'end_character': 1222, 'bleu_score': 0.9450037762840081, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15106752663865142223}, 'section': 'Section::::History.:Construction.:Developed countries.\n'}]}]