Question: when did they stop using aluminum wiring in ontario
[{'answer': 'mid-1970s', 'provenance': [{'wikipedia_id': '2595419', 'title': 'Aluminum building wiring', 'start_paragraph_id': 2, 'start_character': 131, 'end_paragraph_id': 2, 'end_character': 140, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2595419', 'title': 'Aluminum building wiring', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16980565692200219158}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2595419', 'title': 'Aluminum building wiring', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 702, 'bleu_score': 0.982060959997838, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16980565692200219158}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2595419', 'title': 'Aluminum building wiring', 'section': 'Section::::Abstract.', 'start_paragraph_id': 2, 'end_paragraph_id': 2, 'meta': {'evidence_span': ['In North American residential construction, aluminum wire was used for wiring entire houses for a short time from the 1960s to the mid-1970s during a period of high copper prices.', 'aluminum wire was used for wiring entire houses for a short time from the 1960s to the mid-1970s', 'In North American residential construction, aluminum wire was used for wiring entire houses for a short time from the 1960s to the mid-1970s during a period of high copper prices. Electrical devices (outlets, switches, lighting, fans, etc.) at the time were not designed with the particular properties of the aluminum wire being used in mind, and there were some issues related to the properties of the wire itself, making the installations with aluminum wire much more susceptible to problems']}}]}]