Question: when did the himalayan mountains start to form
[{'answer': 'About 50 million years ago', 'provenance': [{'wikipedia_id': '37966', 'title': 'Himalayas', 'start_paragraph_id': 14, 'start_character': 205, 'end_paragraph_id': 14, 'end_character': 231, 'bleu_score': 1.0, 'section': 'Section::::Geology.\n'}]}, {'provenance': [{'wikipedia_id': '37966', 'title': 'Himalayas', 'start_paragraph_id': 14, 'start_character': 0, 'end_paragraph_id': 14, 'end_character': 770, 'bleu_score': 0.9570764685495211, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11133073199165062146}, 'section': 'Section::::Geology.\n'}]}]