The income statement of Cadmium Inc., for the month of January of the current year is as follows:

Revenues		$21,000
Cost of goods sold:
Direct materials	$6,000
Direct labor	4,000
Overhead	2,000	$12,000
Gross profit		$ 9,000
Selling and administrative expenses		2,000
Operating income		$ 7,000

Determine the markup based on cost of goods sold (COGS).