user: ### NOW ANSWER:
Question: What is the 2006 census population when the area is 159?
Columns: ['LGA Name', 'Area (km 2 )', 'Census 2006 population', 'Administrative capital', 'Postal Code']
Types: ['text', 'real', 'real', 'text', 'real']
Sample row: ['Port Harcourt', 109.0, 541115.0, 'Port Harcourt', 500.0]
SQL:

assistant: SELECT COUNT("Census 2006 population") FROM "Table" WHERE "Area (km 2 )" = 159.0;