Question: when did the chargers became the los angeles chargers
[{'answer': '1960', 'provenance': [{'wikipedia_id': '27170', 'title': 'Los Angeles Chargers', 'start_paragraph_id': 1, 'start_character': 321, 'end_paragraph_id': 1, 'end_character': 325, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]