CREATE TABLE table_23841 ("Type" TEXT, "Beam height  ( mm ) " FLOAT, "Flange width  ( mm ) " FLOAT, "Web thickness  ( mm ) " TEXT, "Flange thickness  ( mm ) " TEXT, "Weight  ( kg/m ) " TEXT, "Cross-section area  ( cm 2  ) " TEXT, "Moment of inertia in torsion  ( J )   ( cm 4  ) " TEXT)

What is the flange width (mm) for cross section area (cm 2) 16.4?
SELECT COUNT("Flange width (mm)") FROM table_23841 WHERE "Cross-section area (cm 2 )" = '16.4'
SELECT COUNT("Flange width (mm)") FROM "table_23841" WHERE "Cross-section area (cm 2 )" = '16.4'