user: Question: Name the total number of population per square km with population 1.12006 of 12.757
Columns: ['Urban area', 'Population 1.1.2009', 'Population 1.1.2008', 'Population 1.1.2007', 'Population 1.1.2006', 'Population per square km']
Types: ['text', 'text', 'real', 'text', 'real', 'real']
Sample row: ['Oslo', '876.391', 856.915, '839.423', 825.105, 3.009]
SQL:

assistant: SELECT SUM("Population per square km") FROM "Table" WHERE "Population 1.1.2006" = 12.757;