user: Question: If the number of barangays is 19, what is the population density?
Columns: ['City / Municipality', 'No. of Barangays', 'Area (km²)', 'Population (2010 Census)', 'Pop. density (per km²)']
Types: ['text', 'real', 'text', 'real', 'text']
Sample row: ['Angono', 10.0, '26.22', 102407.0, '3,905.68']
SQL:

assistant: SELECT "Pop. density (per km²)" FROM "Table" WHERE "No. of Barangays" = 19.0;