user: Question:  how many capital with population census 2009 being 284657
Columns: ['Code', 'County', 'Former Province', 'Area (km 2 )', 'Population Census 2009', 'Capital']
Types: ['real', 'text', 'text', 'text', 'real', 'text']
Sample row: [1.0, 'Mombasa', 'Coast', '212.5', 939370.0, 'Mombasa (City)']
SQL:

assistant: SELECT COUNT("Capital") FROM "Table" WHERE "Population Census 2009" = 284657.0;