Question: when was the first census done in kenya
[{'answer': '1948', 'provenance': [{'wikipedia_id': '37641052', 'title': 'Population and housing censuses by country', 'start_paragraph_id': 25, 'start_character': 43, 'end_paragraph_id': 25, 'end_character': 47, 'bleu_score': 1.0, 'section': 'Section::::Africa.:Kenya.\n'}]}, {'provenance': [{'wikipedia_id': '37641052', 'title': 'Population and housing censuses by country', 'start_paragraph_id': 25, 'start_character': 0, 'end_paragraph_id': 25, 'end_character': 299, 'bleu_score': 0.962600167205617, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11138102213050716511}, 'section': 'Section::::Africa.:Kenya.\n'}]}]