Question: where do the largest number of immigrants come from
[{'answer': 'Americas', 'provenance': [{'wikipedia_id': '15051', 'title': 'Immigration to the United States', 'start_paragraph_id': 235, 'start_character': 41, 'end_paragraph_id': 235, 'end_character': 49, 'bleu_score': 1.0, 'section': 'Section::::See also.\n'}]}]