SO₂ is emitted at a rate of 20 kg/s from a 10 km×10 km airshed in an industrial area. Wind blows at a speed of 4 m/s from one direction in that area. Radiation inversion restricts the mixing height to 1200 m. Neglect SO₂ concentration in the incoming air. Assuming emitted SO₂ to be conservative, the steady state SO₂ concentration in the airshed, in μg/m³, is ______ (rounded off to 2 decimal places)