Question: when did the national league and american league merge
[{'answer': '2000', 'provenance': [{'wikipedia_id': '38776', 'title': 'Major League Baseball', 'start_paragraph_id': 1, 'start_character': 519, 'end_paragraph_id': 1, 'end_character': 523, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '38776', 'title': 'Major League Baseball', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 756, 'bleu_score': 0.9400346272745641, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9760217641125125194}, 'section': 'Section::::Abstract.'}]}]