Question: when did the world celebrate it most recent millennium
[{'answer': '2000', 'provenance': [{'wikipedia_id': '37702817', 'title': 'Millennium celebrations', 'start_paragraph_id': 1, 'start_character': 129, 'end_paragraph_id': 1, 'end_character': 133, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]