user: Question: what is the least density (per km²) when the rank is 5 and the Area (km²) is less than 125755?
Columns: ['Rank', 'Province', 'Population (2011)', 'Area (km²)', 'Density (per km²)']
Types: ['text', 'text', 'real', 'real', 'real']
Sample row: ['1', 'Gauteng', 12272263.0, 18178.0, 675.1]
SQL:

assistant: SELECT MIN("Density (per km²)") FROM "Table" WHERE "Rank" = '5' AND "Area (km²)" < 125755.0;