Question: when was the last back to the future movie made
[{'answer': '1990', 'provenance': [{'wikipedia_id': '42993', 'title': 'Back to the Future', 'start_paragraph_id': 3, 'start_character': 785, 'end_paragraph_id': 3, 'end_character': 789, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '42993', 'title': 'Back to the Future', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 835, 'bleu_score': 0.9472676028982071, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10322497119792382395}, 'section': 'Section::::Abstract.'}]}]