Question: when did 2 spaces after a period change
[{'answer': '1950', 'provenance': [{'wikipedia_id': '4103963', 'title': 'Sentence spacing', 'start_paragraph_id': 3, 'start_character': 134, 'end_paragraph_id': 3, 'end_character': 138, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4103963', 'title': 'Sentence spacing', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 696, 'bleu_score': 0.7553414597643751, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13426965971870677568}, 'section': 'Section::::Abstract.'}]}]