Question: in which decade was the ct scanner developed
[{'answer': '1967'}, {'provenance': [{'wikipedia_id': '50982', 'title': 'CT scan', 'start_paragraph_id': 112, 'start_character': 0, 'end_paragraph_id': 112, 'end_character': 367, 'bleu_score': 0.905341140211783, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14827631870438595747}, 'section': 'Section::::History.\n'}]}]