user: Question: What is the sum of the area for the bahawalnagar district with a population more than 134936?
Columns: ['Serial No.', 'District', 'Headquartered City', 'City Population (2009)', 'City Area(km 2 )']
Types: ['real', 'text', 'text', 'real', 'real']
Sample row: [1.0, 'Attock District', 'Attock City', 94620.0, 20.0]
SQL:

assistant: SELECT SUM("City Area(km 2 )") FROM "Table" WHERE "District" = 'bahawalnagar district' AND "City Population (2009)" > 134936.0;