Question: when were kotex pads introduced to the market
[{'answer': '1920', 'provenance': [{'wikipedia_id': '848246', 'title': 'Kotex', 'start_paragraph_id': 2, 'start_character': 218, 'end_paragraph_id': 2, 'end_character': 222, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '848246', 'title': 'Kotex', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 650, 'bleu_score': 0.980097014099621, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6776178957415068210}, 'section': 'Section::::Abstract.'}]}]