Question: when did the lawrence welk show begin and end
[{'answer': '1951', 'provenance': [{'wikipedia_id': '58576', 'title': 'Lawrence Welk', 'start_paragraph_id': 1, 'start_character': 189, 'end_paragraph_id': 1, 'end_character': 193, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': '1982', 'provenance': [{'wikipedia_id': '58576', 'title': 'Lawrence Welk', 'start_paragraph_id': 1, 'start_character': 197, 'end_paragraph_id': 1, 'end_character': 201, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '58576', 'title': 'Lawrence Welk', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 333, 'bleu_score': 0.96188712955549, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8929280061432105696}, 'section': 'Section::::Abstract.'}]}]