user: Question: How much Population (2011) has a Land area (km²) larger than 15.69, and a Population density (per km²) larger than 57.3?
Columns: ['Name', 'Population (2011)', 'Population (2006)', 'Change (%)', 'Land area (km²)', 'Population density (per km²)']
Types: ['text', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Air Ronge', 1043.0, 1032.0, 1.1, 6.0, 173.8]
SQL:

assistant: SELECT SUM("Population (2011)") FROM "Table" WHERE "Land area (km²)" > 15.69 AND "Population density (per km²)" > 57.3;