user: Question: What's the most area of bochum part 2 with a population less than 15911?
Columns: ['Place', 'Code', 'Area (km 2 )', 'Population', 'Most spoken language']
Types: ['text', 'real', 'real', 'real', 'text']
Sample row: ['Alldays', 90901.0, 11.75, 385.0, 'Northern Sotho']
SQL:

assistant: SELECT MAX("Area (km 2 )") FROM "Table" WHERE "Place" = 'bochum part 2' AND "Population" < 15911.0;