Question: who has the highest ppg average in nba history
[{'answer': 'Wilt Chamberlain', 'provenance': [{'wikipedia_id': '9733533', 'title': 'List of National Basketball Association annual scoring leaders', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '9733533', 'title': 'List of National Basketball Association annual scoring leaders', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 434, 'bleu_score': 0.733176877043035, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12791049715258975958}, 'section': 'Section::::Abstract.'}]}]