Question: when was pslv launched for the first time
[{'answer': '20 September 1993', 'provenance': [{'wikipedia_id': '87327', 'title': 'Polar Satellite Launch Vehicle', 'start_paragraph_id': 9, 'start_character': 31, 'end_paragraph_id': 9, 'end_character': 48, 'bleu_score': 1.0, 'section': 'Section::::Development.\n'}]}]