Question: when did they change the nba finals format
[{'answer': '2007', 'provenance': [{'wikipedia_id': '12106552', 'title': 'NBA playoffs', 'start_paragraph_id': 42, 'start_character': 12, 'end_paragraph_id': 42, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::History.:Timeline.\n'}]}, {'provenance': [{'wikipedia_id': '12106552', 'title': 'NBA playoffs', 'start_paragraph_id': 42, 'start_character': 0, 'end_paragraph_id': 42, 'end_character': 684, 'bleu_score': 0.819661231448883, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1446823402457296536}, 'section': 'Section::::History.:Timeline.\n'}]}]