Question: when did san francisco become a sanctuary city
[{'answer': '1989', 'provenance': [{'wikipedia_id': '10511069', 'title': 'Sanctuary city', 'start_paragraph_id': 66, 'start_character': 63, 'end_paragraph_id': 66, 'end_character': 67, 'bleu_score': 1.0, 'section': 'Section::::United States.:Laws and policies by state and city.:California.\n'}]}]