Question: when did walvis bay become part of namibia
[{'answer': '1 March 1994', 'provenance': [{'wikipedia_id': '42895', 'title': 'Walvis Bay', 'start_paragraph_id': 18, 'start_character': 257, 'end_paragraph_id': 18, 'end_character': 269, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '42895', 'title': 'Walvis Bay', 'start_paragraph_id': 18, 'start_character': 0, 'end_paragraph_id': 18, 'end_character': 269, 'bleu_score': 0.552673806421906, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5200822937628507391}, 'section': 'Section::::History.\n'}]}]