Question: when did the chevy silverado change body styles
[{'answer': '2007.5 MY', 'provenance': [{'wikipedia_id': '865341', 'title': 'Chevrolet Silverado', 'start_paragraph_id': 25, 'start_character': 465, 'end_paragraph_id': 25, 'end_character': 474, 'bleu_score': 1.0, 'section': 'Section::::First generation (1999–2007).:Light duty.:Chevrolet Silverado SS.:Intimidator SS.\n'}]}, {'provenance': [{'wikipedia_id': '865341', 'title': 'Chevrolet Silverado', 'start_paragraph_id': 25, 'start_character': 0, 'end_paragraph_id': 25, 'end_character': 609, 'bleu_score': 0.9066294609209791, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13162852170379449633}, 'section': 'Section::::First generation (1999–2007).:Light duty.:Chevrolet Silverado SS.:Intimidator SS.\n'}]}]