Question: when did nebraska became a right to work state
[{'answer': '1946', 'provenance': [{'wikipedia_id': '392198', 'title': 'Right-to-work law', 'start_paragraph_id': 58, 'start_character': 43, 'end_paragraph_id': 58, 'end_character': 47, 'bleu_score': 1.0, 'section': 'Section::::U.S. states with right-to-work laws.\n'}]}, {'provenance': [{'wikipedia_id': '392198', 'title': 'Right-to-work law', 'start_paragraph_id': 70, 'start_character': 0, 'end_paragraph_id': 70, 'end_character': 60, 'bleu_score': 0.6803749333171201, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13656629741002071132}, 'section': 'Section::::U.S. states with right-to-work laws.\n'}]}]