Question: when did the first television go on sale
[{'answer': '1938', 'provenance': [{'wikipedia_id': '169672', 'title': 'List of years in television', 'start_paragraph_id': 10, 'start_character': 12, 'end_paragraph_id': 10, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::1930s.\n'}]}, {'provenance': [{'wikipedia_id': '169672', 'title': 'List of years in television', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 516, 'bleu_score': 0.923732788176137, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8131772721442110242}, 'section': 'Section::::1930s.\n'}]}]