user: Question: How many weights are there when the flange with is 304?
Columns: ['Type', 'Beam height (mm)', 'Flange width (mm)', 'Web thickness (mm)', 'Flange thickness (mm)', 'Weight (kg/m)', 'Cross-section area (cm 2 )', 'Moment of inertia in torsion (J) (cm 4 )']
Types: ['text', 'real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: ['HE 100 A', 96.0, 100.0, '5', '8', '16.7', '21.2', '5.24']
SQL:

assistant: SELECT COUNT("Weight (kg/m)") FROM "Table" WHERE "Flange width (mm)" = 304.0;