Question: when did they start using titanium in surgery
[{'answer': 'the 1950s', 'provenance': [{'wikipedia_id': '37422114', 'title': 'Titanium biocompatibility', 'start_paragraph_id': 1, 'start_character': 48, 'end_paragraph_id': 1, 'end_character': 57, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '37422114', 'title': 'Titanium biocompatibility', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 939, 'bleu_score': 0.985662154730604, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 171444833265850364}, 'section': 'Section::::Abstract.'}]}]